Solve $\sqrt { 7 x - 6 } + 1 = 7$

Multiple Choice

Solve: $\sqrt { 7 x - 6 } + 1 = 7$

A) $\left\{ - \frac { 15 } { 7 } \right\}$
B) $\left\{ \frac { 29 } { 7 } \right\}$
C) $\{ 6 \}$
D) $\left\{ - \frac { 30 } { 7 } \right\}$