If f(a)=a^2, what is the value of (f(a+b)−f(b))/b ?	Choose the correct choice from the following choices:
A) 2a+a^2
B) b
C) 2a
D) 2a + b
E) 2b - a
start with f(a+b) before start calculations: f(a+b)=(a+b)^2= a^2+2ab+b^2   a^2+2ab+b^2 - b^2/b = (simplify a^2)   2ab+a^2/b = (cancel b's)   = 2a+a^2   2a+a^2ns : 2a+a^2
<result>A</result>
If f(a)=a^2, what is the value of (f(a+b)−f(b))/b ?