Multiply, and Then Simplify If Possible $( \sqrt { 11 } + \sqrt { 6 } ) ( \sqrt { 11 } - \sqrt { 6 } )$

Multiple Choice

Multiply, and then simplify if possible. Assume all variables represent positive real numbers.
- $( \sqrt { 11 } + \sqrt { 6 } ) ( \sqrt { 11 } - \sqrt { 6 } )$

A) $11 - 2 \sqrt { 6 }$
B) $11 - 2 \sqrt { 11 }$
C) 5
D) 17