Assume That the Expressions Given Are Denominators of Fractions $a+b, a-b, a^{2}-b^{2}$

Multiple Choice

Assume that the expressions given are denominators of fractions. Find the least common denominator.
- $a+b, a-b, a^{2}-b^{2}$

A) $b(a+b)$
B) $(a+b) ^{2}(a-b) ^{2}$
C) $a(a-b)$
D) $(a+b) (a-b)$