Perform the Indicated Operations $\left[ \left( 1.1 x ^ { 3 } + 7.9 x ^ { 2 } + 4.2 \right) + ( 6.2 x - 2.3 ) \right] - \left( 3.7 x ^ { 2 } - x - 9.9 \right)$

Multiple Choice

Perform the indicated operations.
- $\left[ \left( 1.1 x ^ { 3 } + 7.9 x ^ { 2 } + 4.2 \right) + ( 6.2 x - 2.3 ) \right] - \left( 3.7 x ^ { 2 } - x - 9.9 \right)$

A) $1.1 x ^ { 3 } + 4.2 x ^ { 2 } + 6.2 x + 11.8$
B) $12.5 x ^ { 6 } + 11.8$
C) $1.1 x ^ { 3 } + 11.6 x ^ { 2 } + 5.2 x - 8$
D) $1.1 x ^ { 3 } + 4.2 x ^ { 2 } + 7.2 x + 11.8$