I can predict a couple of reasons why x≠0 is given in the question stem. It’s customary for the GMAT to provide such information and convey that certain things are not defined on the GMAT.
Division by ZERO is not defined on the GMAT
\(0^0\) is not defined on the GMAT
These are two things that this question is hinting at by giving x≠0.
Breaking down the expression given in the question stem, we need to find the value of \([x^{(p-q)}]^4\) or \(x^{4(p-q)}\)
From statement I alone, p = q.
Therefore, p – q = 0. Substituting this value in the expression, we see that we need to find the value of \(x^{4(0)}\) or \(x^0\). Since x≠0, \(x^0\) = 1.
Statement I alone is sufficient. Answer options B, C and E can be eliminated.
From statement II alone, x = 3.
Therefore, the given expression can be written as \(3^{4(p-q)}\). Unless we are given the value of (p-q), it is not possible to evaluate the value of this expression.
Statement II alone is insufficient. Answer option D can be eliminated.
The correct answer option is A.
Hope that helps!
Aravind BT