Factor the Greatest Common Factor from the Polynomial $28 x ^ { 2 n } - 20 x ^ { n }$

Multiple Choice

Factor the greatest common factor from the polynomial. Assume any variable exponents represent whole numbers.
- $28 x ^ { 2 n } - 20 x ^ { n }$

A) $4 x ^ { n } \left( 7 x ^ { n } - 5 x \right)$
B) $4 x ^ { 2 n } \left( 7 x ^ { n } - 5 \right)$
C) $4 x ^ { 2 } \left( 7 x ^ { n } - 5 \right)$
D) $4 x ^ { n } \left( 7 x ^ { n } - 5 \right)$