\(p^a\cdot q^b\cdot r^c\cdot s^d=x,\) where \(x\) is a perfect square. If \(p, q, r,\) and \(s\) are prime integers, are they distinct?
(1) \(18\) is a factor of \(ab\) and \(cd.\)
(2) \(4\) is not a factor of \(ab\) and \(cd.\)
Answer: B
Source: Manhattan GMAT