Factor by Grouping $15 x ^ { 4 } + 20 x ^ { 2 } - 12 x ^ { 2 } - 16$

Multiple Choice

Factor by grouping.
- $15 x ^ { 4 } + 20 x ^ { 2 } - 12 x ^ { 2 } - 16$

A) $\left( 5 x ^ { 2 } - 4 \right) \left( 3 x ^ { 2 } + 4 \right)$
B) $\left( 5 x ^ { 2 } + 4 \right) \left( 3 x ^ { 2 } - 4 \right)$
C) $\left( 15 x ^ { 2 } + 4 \right) \left( x ^ { 2 } - 4 \right)$
D) $\left( 5 x ^ { 4 } - 4 \right) ( 3 x + 4 )$