Answer: The correct option is
(C) 36.
Step-by-step explanation: We are given to select the value that completes the square or creates a perfect square trinomial for the following incomplete expression :

We will be using the following square formula :

Let the required value be represented by c.
We have

So, for the given expression to be a perfect square trinomial, we must have

Thus, the required value is 36.
Option (C) is CORRECT.