If a and b are positive integers and b ≠ 1, then ab(b −1) is	Choose the correct answer.
A) ab^2-ab B) 2/b C) 1/b D) 1/a E) 1/a+1/b
ab^2-abnswer : ab^2-ab
<result>A</result>
If a and b are positive integers and b ≠ 1, then ab(b −1) is