Task: Question Answering
Input (English): For all positive integers p and q, let \(\Phi\) be defined by \(p \Phi q = (p + Q)^2 - (p - q)^2\). If \(a\) and \(b\) are positive integers, which of the following CANNOT be the value of \(a \Phi b\)?
(A)4 (B)8 (C)12 (D)18 (E)20
Output (English): D