Multiply Using the Rule for the Product of the Sum $\left( 5 a ^ { n } + 4 \right) \left( 5 a ^ { n } - 4 \right)$

Multiple Choice

Multiply using the rule for the product of the sum and difference of two terms. Assume any variable exponents represent whole numbers.
- $\left( 5 a ^ { n } + 4 \right) \left( 5 a ^ { n } - 4 \right)$

A) $25 a ^ { n } - 16$
B) $5 a ^ { 2 n } - 16$
C) $25 a ^ { 2 n } + 40 a ^ { n } - 16$
D) $25 a ^ { 2 n } - 16$