Add or Subtract $4 \sqrt { 3 } + 2 \sqrt { 27 }$

Multiple Choice

Add or subtract. Assume all variables represent positive real numbers.
- $4 \sqrt { 3 } + 2 \sqrt { 27 }$

A) $10 \sqrt { 3 }$
B) $- 10 \sqrt { 3 }$
C) $6 \sqrt { 3 }$
D) $2 \sqrt { 3 }$