Decide What Number Must Be Added to the Binomial to Make

Multiple Choice

Decide what number must be added to the binomial to make a perfect square trinomial.
- $$( 2 x + 5 ) ^ { 2 } = 49$$

A) $\{ - 6,1 \}$
B) $\{ - 27,27 \}$
C) $\{ 1,6 \}$
D) $\{ 0,1 \}$