Why is the gravitational potential energy of an object 1 meter above the moon’s surface less than its potential energy 1 meter above earth’s surface? a. the object’s mass is less on the moon. b. the object’s weight is more on the moon. c. the object’s acceleration due to gravity is less on the moon. d. both a and c

If you remember the formula for potential energy,
then this question is a piece-o-cake.

  Potential energy = (mass) x (acceleration of gravity) x (height) .

-- The object's mass is the same everywhere.
-- You said that the height is the same both times.
-- How about the acceleration of gravity ? 

Compared to gravity on Earth, it's only  16.5 percent as much on the Moon. 
So naturally, from the formula, you'd expect the Potential Energy to be less
on the Moon.