What Inputs Are Defined for the Expression $$\frac { x } { 3 x - 7 }$$

Multiple Choice

What inputs are defined for the expression? $$\frac { x } { 3 x - 7 }$$

A) $R , x \neq - \frac { 7 } { 3 }$
B) $\mathrm { R } , x \neq - \frac { 3 } { 7 }$
C) $R , x \neq \frac { 3 } { 7 }$
D) $R , x \neq \frac { 7 } { 3 }$
E) $R , x \neq 0$