Simplify Assume That Variables Represent Positive Real Numbers $3 x ^ { 5 / 7 }$

Multiple Choice

Simplify. Assume that variables represent positive real numbers.
- $3 x ^ { 5 / 7 }$

A) $\sqrt [ 5 ] { 3 x ^ { 7 } }$
B) $\sqrt [ 7 ] { 243 x ^ { 5 } }$
C) $\sqrt [ 7 ] { 3 x ^ { 5 } }$
D) $3 \sqrt [ 7 ] { \mathrm { x } ^ { 5 } }$