Use the Product Rule to Multiply $\sqrt { 6 } \cdot \sqrt { 7 }$

Multiple Choice

Use the product rule to multiply. Assume all variables represent positive real numbers.
- $\sqrt { 6 } \cdot \sqrt { 7 }$

A) $\sqrt { 42 }$
B) $\sqrt { 13 }$
C) 42
D) $\sqrt { 6 + 7 }$