Find the Sum or Difference $$\left( 2 a ^ { 4 } + 6 a ^ { 3 } \right) + \left( 6 a ^ { 4 } + 8 a ^ { 3 } \right)$$

Multiple Choice

Find the sum or difference.
- $$\left( 2 a ^ { 4 } + 6 a ^ { 3 } \right) + \left( 6 a ^ { 4 } + 8 a ^ { 3 } \right)$$

A) $8 a ^ { 8 } + 14 a ^6$
B) $22 \mathrm { a } ^ { 7 }$
C) $22 a ^{14}$
D) $8 a ^ { 4 } + 14 a ^ { 3 }$