The domain of a function involving a square root requires that the expression inside the square root be non-negative. Therefore, for the function \( f(x) = \sqrt{7 - 11x} \), we need:
\[
7 - 11x \geq 0
\]
Solving for \( x \):
\[
7 \geq 11x
\]
\[
x \leq \frac{7}{11}
\]
Thus, the domain of \( f(x) \) is \( x \leq \frac{7}{11} \), which corresponds to option (A).