What is the value of c such that: x2 + 14x + c, is a perfect-square trinomial?

A. 7

B. 98

C. 196

D. 49

We know that in a perfect square trinomial, the terms are:

a² + b² + 2ab

Here we have x = a. So b is:

14x = 2 (x) (b)

b = 7

To complete the trinomial, we need b²

7² = 49

Option D is the answer