Factor Completely $16 x ^ { 4 } + 56 x ^ { 3 } - 32 x ^ { 2 }$

Multiple Choice

Factor completely. If the polynomial cannot be factored, write ʺprime.ʺ
- $16 x ^ { 4 } + 56 x ^ { 3 } - 32 x ^ { 2 }$

A) $8 x ( 2 x + 1 ) ( x - 4 )$
B) $8 x ^ { 2 } ( 2 x - 1 ) ( x + 4 )$
C) $x ^ { 2 } ( 2 x - 1 ) ( 8 x + 32 )$
D) $\left( 16 x ^ { 2 } - 8 \right) \left( x ^ { 2 } + 4 \right)$