Which of the following is a perfect square trinomial?A.16x2 + 56xy - 49y2B.16x2 + 22xy - 49y2C.16x2 - 56xy + 49y2D.16x2 - 22xy + 49y2

A perfect square trinomial is a trinomial that can be factored into the square of a binomial. This means that the trinomial can be written in the form (ax + by)^2 or (ax - by)^2.

Let's check each option:

A. 16x^2 + 56xy - 49y^2 This cannot be a perfect square trinomial because the last term is negative.

B. 16x^2 + 22xy - 49y^2 This cannot be a perfect square trinomial because the last term is negative.

C. 16x^2 - 56xy + 49y^2 This can be factored into (4x - 7y)^2, so it is a perfect square trinomial.

D. 16x^2 - 22xy + 49y^2 This cannot be factored into the square of a binomial, so it is not a perfect square trinomial.

So, the answer is C. 16x^2 - 56xy + 49y^2.