Answer:
Option D, x ≤ 11
Explanation:
We have to determine the domain of the function.
f(x) =

This function is defined for the positive values of ( 11 - x ) because under root of negative terms is not defined.
Therefore, domain of the given function will be ( 11 - x ) ≥ 0
x ≤ 11
Option D, x ≤ 11 is the answer.