Find the number to add to x^2+8x to make it a perfect square trinomial. Write that trinomial as the square of a binomial.

A) add 64; (x+8)^2
B) add 16; (x+4)^2
C) add 16; (x+8)^2
D) add 8; (x+4)^2

B) add 16; (x+4)^2