Use the Product Rule to Multiply $\sqrt [ 4 ] { 16 } \cdot \sqrt [ 4 ] { 256 }$

Multiple Choice

Use the product rule to multiply. Assume all variables represent positive real numbers.
- $\sqrt [ 4 ] { 16 } \cdot \sqrt [ 4 ] { 256 }$

A) 6
B) $- 8$
C) $- 2$
D) 8