Which of the following represents the force corresponding to the given potential?
[asy]
// Code by riben
size(400);
picture pic;
// Rectangle
draw(pic,(0,0)--(22,0)--(22,12)--(0,12)--cycle);
label(pic,"-15",(2,0),S);
label(pic,"-10",(5,0),S);
label(pic,"-5",(8,0),S);
label(pic,"0",(11,0),S);
label(pic,"5",(14,0),S);
label(pic,"10",(17,0),S);
label(pic,"15",(20,0),S);
label(pic,"-2",(0,2),W);
label(pic,"-1",(0,4),W);
label(pic,"0",(0,6),W);
label(pic,"1",(0,8),W);
label(pic,"2",(0,10),W);
label(pic,rotate(90)*"F (N)",(-2,6),W);
label(pic,"x (m)",(11,-2),S);
// Tick Marks
draw(pic,(2,0)--(2,0.3));
draw(pic,(5,0)--(5,0.3));
draw(pic,(8,0)--(8,0.3));
draw(pic,(11,0)--(11,0.3));
draw(pic,(14,0)--(14,0.3));
draw(pic,(17,0)--(17,0.3));
draw(pic,(20,0)--(20,0.3));
draw(pic,(0,2)--(0.3,2));
draw(pic,(0,4)--(0.3,4));
draw(pic,(0,6)--(0.3,6));
draw(pic,(0,8)--(0.3,8));
draw(pic,(0,10)--(0.3,10));
draw(pic,(2,12)--(2,11.7));
draw(pic,(5,12)--(5,11.7));
draw(pic,(8,12)--(8,11.7));
draw(pic,(11,12)--(11,11.7));
draw(pic,(14,12)--(14,11.7));
draw(pic,(17,12)--(17,11.7));
draw(pic,(20,12)--(20,11.7));
draw(pic,(22,2)--(21.7,2));
draw(pic,(22,4)--(21.7,4));
draw(pic,(22,6)--(21.7,6));
draw(pic,(22,8)--(21.7,8));
draw(pic,(22,10)--(21.7,10));
// Paths
path A=(0,6)--(5,6)--(5,4)--(11,4)--(11,8)--(17,8)--(17,6)--(22,6);
path B=(0,6)--(5,6)--(5,2)--(11,2)--(11,10)--(17,10)--(17,6)--(22,6);
path C=(0,6)--(5,6)--(5,5)--(11,5)--(11,7)--(17,7)--(17,6)--(22,6);
path D=(0,6)--(5,6)--(5,7)--(11,7)--(11,5)--(17,5)--(17,6)--(22,6);
path E=(0,6)--(5,6)--(5,8)--(11,8)--(11,4)--(17,4)--(17,6)--(22,6);
draw(A);
label("(A)",(9.5,-3),4*S);
draw(shift(35*right)*B);
label("(B)",(45.5,-3),4*S);
draw(shift(20*down)*C);
label("(C)",(9.5,-23),4*S);
draw(shift(35*right)*shift(20*down)*D);
label("(D)",(45.5,-23),4*S);
draw(shift(40*down)*E);
label("(E)",(9.5,-43),4*S);
add(pic);
picture pic2=shift(35*right)*pic;
picture pic3=shift(20*down)*pic;
picture pic4=shift(35*right)*shift(20*down)*pic;
picture pic5=shift(40*down)*pic;
add(pic2);
add(pic3);
add(pic4);
add(pic5);
[/asy]
To determine the force corresponding to the given potential, we use the relationship between force and potential energy. The force \( F \) in the \( x \)-direction is given by the negative gradient of the potential energy \( U \):

\[ F_x = -\frac{dU}{dx} \]

We need to analyze the given potential energy graph and compute its derivative to find the force.

1. **Identify the segments of the potential energy graph:**
   - From \( x = -15 \) to \( x = -10 \), the potential energy \( U \) is constant.
   - From \( x = -10 \) to \( x = 0 \), the potential energy \( U \) decreases linearly.
   - From \( x = 0 \) to \( x = 10 \), the potential energy \( U \) increases linearly.
   - From \( x = 10 \) to \( x = 15 \), the potential energy \( U \) is constant.

2. **Compute the derivative of \( U \) with respect to \( x \):**
   - For \( x \) in the range \( -15 \leq x < -10 \) and \( 10 < x \leq 15 \), \( U \) is constant, so \( \frac{dU}{dx} = 0 \).
   - For \( x \) in the range \( -10 \leq x < 0 \), \( U \) decreases linearly. The slope of this segment is negative. Let’s denote the slope as \( m_1 \). Since the potential decreases, \( m_1 < 0 \).
   - For \( x \) in the range \( 0 \leq x \leq 10 \), \( U \) increases linearly. The slope of this segment is positive. Let’s denote the slope as \( m_2 \). Since the potential increases, \( m_2 > 0 \).

3. **Determine the slopes \( m_1 \) and \( m_2 \):**
   - The slope \( m_1 \) from \( x = -10 \) to \( x = 0 \) is calculated as:
     \[
     m_1 = \frac{\Delta U}{\Delta x} = \frac{U(0) - U(-10)}{0 - (-10)} = \frac{U(0) - U(-10)}{10}
     \]
   - The slope \( m_2 \) from \( x = 0 \) to \( x = 10 \) is calculated as:
     \[
     m_2 = \frac{\Delta U}{\Delta x} = \frac{U(10) - U(0)}{10 - 0} = \frac{U(10) - U(0)}{10}
     \]

4. **Compute the force \( F_x \):**
   - For \( x \) in the range \( -15 \leq x < -10 \) and \( 10 < x \leq 15 \), \( F_x = 0 \).
   - For \( x \) in the range \( -10 \leq x < 0 \), \( F_x = -m_1 \). Since \( m_1 \) is negative, \( F_x \) is positive.
   - For \( x \) in the range \( 0 \leq x \leq 10 \), \( F_x = -m_2 \). Since \( m_2 \) is positive, \( F_x \) is negative.

5. **Match the force graph with the given options:**
   - The force graph should show \( F_x = 0 \) for \( x \) in the ranges \( -15 \leq x < -10 \) and \( 10 < x \leq 15 \).
   - The force graph should show a positive constant value for \( x \) in the range \( -10 \leq x < 0 \).
   - The force graph should show a negative constant value for \( x \) in the range \( 0 \leq x \leq 10 \).

By examining the given options, we find that option \( E \) matches these criteria. Therefore, the correct answer is:

\[
\boxed{E}
\]