If \(x\) and \(y\) are positive numbers and \(z = xy^2,\) a \(50\) percent increase in \(x\) and a \(20\) percent decrease in \(y\) would result in which of the following changes in \(z?\)
(A) A decrease of \(4\%\)
(B) A decrease of \(14\%\)
(C) An increase of \(4\%\)
(D) An increase of \(20\%\)
(E) An increase of \(30\%\)
Answer: A
Source: GMAT Paper Tests