Suppose That H(x) = X² + 2x + 1, with the Domain

Suppose that h(x) = x² + 2x + 1, with the domain of h being the set of positive numbers. Evaluate h ^-1(6) .

A) $1-\sqrt{6}$
B) $1+\sqrt{6}$
C) $\sqrt{6}$
D) $\sqrt{6}-1$