Multiply, Then Simplify the Product $(\sqrt{13}+1)(\sqrt{13}-1)$ A) $12-2 \sqrt{13}$ B) 14
C) 12
D)

Multiple Choice

Multiply, then simplify the product. Assume that all variables represent positive real numbers.
- $(\sqrt{13}+1) (\sqrt{13}-1)$

A) $12-2 \sqrt{13}$
B) 14
C) 12
D) $12+2 \sqrt{13}$