$$\log _ { 9 } \left( x ^ { 2 } + 2 x + 1 \right) = t \quad ( x > - 1 )$$
Given this equation, which of the following is the expression for x in terms of t?\\
A) $3 ^ { t } - 1$\\
B) $3 ^ { \mathrm { t } - 1 }$\\
C) $3 - 2 ^ { t }$\\
D) $2 \cdot 3 ^ { \mathrm { t } - 1 }$\\
E) $3 ^ { t } - 2$