Simplify the Following by Combining Like Terms $- 6 r - 2 r ^ { 4 } - 6 r ^ { 4 } - 6 r$

Multiple Choice

Simplify the following by combining like terms.
- $- 6 r - 2 r ^ { 4 } - 6 r ^ { 4 } - 6 r$

A) $- 20 r ^ { 4 }$
B) $- 20 r$
C) $- 12 r - 8 r ^ { 4 }$
D) cannot be simplified