Add or Subtract $$2 \sqrt [ 4 ] { 6 } + 3 \sqrt [ 3 ] { 6 }$$

Multiple Choice

Add or subtract. Assume all variables represent positive real numbers.
- $$2 \sqrt [ 4 ] { 6 } + 3 \sqrt [ 3 ] { 6 }$$

A) $5 \sqrt [ 3 ] { 6 }$
B) $5 \sqrt [ 4 ] { 6 }$
C) $6 \sqrt [ 4 ] { 36 }$
D) $2 \sqrt [ 4 ] { 6 } + 3 \sqrt [ 3 ] { 6 }$