Determine Which $x$ -Value Below Is a Solution of the Equation $\log _ { 7 } \left( \frac { 5 } { 3 } x \right) = 3$

Multiple Choice

Determine which $x$ -value below is a solution of the equation $\log _ { 7 } \left( \frac { 5 } { 3 } x \right) = 3$ .
$$x = \frac { 21 } { 125 } , x = \frac { 1029 } { 5 } , x = \frac { 189 } { 5 } , x = 21 , x = 15$$

A) $x = \frac { 21 } { 125 }$

B) $x = \frac { 1029 } { 5 }$

C) $x = \frac { 189 } { 5 }$

D) $x = 21$

E) $x = 15$