15 joules of work are done by forces other than gravity in taking an object from a position 3 m above the ground to a position 8 m above the ground. What is the change in the gravitational potential energy of the object?
o A. It decreases by 5 joules.
o B. It increases by 5 joules.
o C. It increases by 11 joules.
o D. It increases by 15 joules.