Perform the Indicated Operation $\left[ \left( 1.8 x ^ { 3 } + 7.1 x ^ { 2 } + 4.5 \right) + ( 6.6 x - 2.1 ) \right] - \left( 3.5 x ^ { 2 } - x - 9.8 \right)$

Multiple Choice

Perform the indicated operation.
- $\left[ \left( 1.8 x ^ { 3 } + 7.1 x ^ { 2 } + 4.5 \right) + ( 6.6 x - 2.1 ) \right] - \left( 3.5 x ^ { 2 } - x - 9.8 \right)$

A) $1.8 x ^ { 3 } + 3.6 x ^ { 2 } + 6.6 x + 12.2$
B) $1.8 x ^ { 3 } + 3.6 x ^ { 2 } + 7.6 x + 12.2$
C) $1.8 x ^ { 3 } + 10.6 x ^ { 2 } + 5.6 x - 7.4$
D) $13 x ^ { 6 } + 12.2$