Simplify the Expression $\left( x ^ { 9 } \right) ^ { 5 }$

Multiple Choice

Simplify the expression. Write your answer with positive exponents only. $\left( x ^ { 9 } \right) ^ { 5 }$

A) $x ^ { 59,049 }$
B) $x ^ { 4 }$
C) $x ^ { 45 }$
D) $x ^ { 14 }$