A6. If we simplify the expression $\frac{a^{-2} b^{-1}}{a^{-2} b^{-1}}: a^{-1} b$, we get:
(A) 0
(B) $a b^{-1}$
(C) $a^{-1} b^{-1}$
(D) $a^{-1} b$
(E) $a b$

## II. DEL
A6. The fraction in the expression is simplified to: $1: \frac{1}{a} \cdot b$, which is equal to $a b$.

## II. PART