Astudent examines the diagram shown below of several metal spheres of equal mass resting on different shelves.

the student plans to make a bar graph comparing the potential energies of the spheres. which statement best compares two of the bars that should be used in the graph?

a. the bar representing sphere 3 should be twice as tall as the bar representing sphere 1.

b. the bar representing sphere 3 should be twice as tall as the bar representing sphere 2.

c. the bar representing sphere 1 should be twice as tall as the bar representing sphere 2.

d. the bar representing sphere 4 should be twice as tall as the bar representing sphere 2.