If \(ab=x\) and \(\dfrac{a}{b}=y,\) and \(ab\) does not equal zero, then \(a^2-b^2=\)

[Gmat_mission]

If \(ab=x\) and \(\dfrac{a}{b}=y,\) and \(ab\) does not equal zero, then \(a^2-b^2=\)

A. \(\dfrac{x(y-1)(y+1)}{y}\)

B. \(xy-\dfrac{y}{x}\)

C. \(x^2-y^2\)

D. \(y\left(x^2-\dfrac1{x^2}\right)\)

E. \(\dfrac{(y+x)(y-x)}{x}\)


Answer: A

Source: Manhattan GMAT