My grandparents are Arthur, Bertha, Christoph, and Dolores. My oldest grandparent is only $4$ years older than my youngest grandparent. Each grandfather is two years older than his wife. If Bertha is younger than Dolores, what is the difference between Bertha's age and the mean of my grandparents’ ages?

$\textbf{(A) }0\hspace{14em}\textbf{(B) }1\hspace{14em}\textbf{(C) }2$

$\textbf{(D) }3\hspace{14em}\textbf{(E) }4\hspace{14em}\textbf{(F) }5$

$\textbf{(G) }6\hspace{14em}\textbf{(H) }7\hspace{14em}\textbf{(I) }8$

$\textbf{(J) }2007$
1. Let Bertha, the younger grandmother, be \( x \) years old. Then her husband, Arthur, is \( x + 2 \) years old.
2. Since Bertha is younger than Dolores, Dolores must be the other grandmother. Let Dolores be \( y \) years old, and her husband, Christoph, be \( y + 2 \) years old.
3. The problem states that the oldest grandparent is only 4 years older than the youngest grandparent. Therefore, we have:
   \[
   y + 2 = x + 4
   \]
4. Solving for \( y \):
   \[
   y + 2 = x + 4 \implies y = x + 2
   \]
5. Now we have the ages of all grandparents:
   - Bertha: \( x \)
   - Arthur: \( x + 2 \)
   - Dolores: \( x + 2 \)
   - Christoph: \( x + 4 \)
6. The mean of the grandparents' ages is:
   \[
   \text{Mean} = \frac{x + (x + 2) + (x + 2) + (x + 4)}{4} = \frac{4x + 8}{4} = x + 2
   \]
7. The difference between Bertha's age and the mean of the grandparents' ages is:
   \[
   (x + 2) - x = 2
   \]

The final answer is \(\boxed{2}\).