The question is asking us to find the coordinates of vertical line segment that is 4 units long. Any vertical line has the x value same .
Among all the options given (3, –8) and (3, –4) have x ordinates same. The distance between the points = [ -8-(-4) ] = l (-8+4)l = 4 units
The points (3, –8) and (3, –4) are vertical line segment and is 4 units long .