the complete question in the attached figure
we know that
The distance of the point (7, 8.75) to the x-axis (the horizontal line) is 8.75
then
case A) (-7, 5.25)---------> is not correct ( the distance to the x-axis is 5.25)
case B) (8.75, 6)---------> is not correct ( the distance to the x-axis is 6)
case C) (6, -8.75)---------> is correct ( the distance to the x-axis is 8.75)
the answer is the option C) (6, -8.75)