Use the Power Rule and the Power of a Product $\left( x ^ { 7 } y \right) ^ { 3 }$

Multiple Choice

Use the power rule and the power of a product or quotient rule to simplify the expression.
- $\left( x ^ { 7 } y \right) ^ { 3 }$

A) $\mathrm { x } ^ { 10 } \mathrm { y } ^ { 4 }$
B) $x ^ { 21 } y ^ { 3 }$
C) $x ^ { 10 } y$
D) $x ^ { 21 } y$