Let the operation \(\blacktriangle\) be defined by \(a \blacktriangle b = a^b - b^a\) for all positive integers \(a\) and \(b\), where \(a \neq b\). If \(2 \blacktriangle x = x \blacktriangle 2\), where \(x\) is a positive integer, what is the value of \(x\) ?
(A)8 (B)6 (C)4 (D)2 (E)1
C