Factor the Trinomial Completely $5 r ^ { 6 } - 15 r ^ { 5 } - 50 r ^ { 4 }$

Multiple Choice

Factor the trinomial completely. If the polynomial cannot be factored, write "prime."
- $5 r ^ { 6 } - 15 r ^ { 5 } - 50 r ^ { 4 }$

A) $5 r ^ { 4 } ( r - 2 ) ( r + 5 )$
B) $\left( 5 r ^ { 3 } + 25 \right) ( r - 2 )$
C) $\left( 5 r ^ { 3 } + 10 \right) ( r - 5 )$
D) $5 r ^ { 4 } ( r + 2 ) ( r - 5 )$