In the \(xy\)-coordinate plane, what are the \(x\)-coordinates of the four vertices of square \(JKMN?\)
(1) \(J\) and \(M\) are on the \(x\)-axis and \(K\) and \(N\) are on the \(y\)-axis.
(2) The center of the square is at the origin.
Answer: E
Source: Official Guide