The coordinates have opposite signs. which choice includes all the quadrants that could contain the point?

There are only 2 possible choices: the point can be either in quadrant 2 or in quadrant 4.

In fact, if it is in quadrant 2, the point has negative x-coordinate and positive y-coordinate, while if it is in quadrant 4, it has positive x-coordinate and negative y-coordinate, so in both cases the two coordinates have opposite signs.

Instead, in quadrant 1 both x- and y- coordinates have same sign (positive), and in quadrant 3 both x- and y- coordinates have same sign (negative), so these choices are not correct.