Answer:
D. .
Step-by-step explanation:
We have been given a trinomial . We are asked to find the value of c, which will make the expression a perfect square trinomial.
We know that a perfect trinomial is in form .
We will use complete the square process to solve for c.
To complete a square, we need to add square of half the coefficient of x term. We can see that coefficient of x is -7, so the value of c would be:
.
Therefore, the value of c required to make the given expression a perfect trinomial is and option D is the correct choice.