PLEASE HELP FAST!! BRAINLEST AND 30 POINTS

In a diagram of bond energy and length, why does the potential energy initially decrease as you move to the right from the y-axis?

A. The repulsion of the protons is increasing.
B. The repulsion of the protons is decreasing.
C. The attraction of the protons to the electrons is increasing.
D. The attraction of the protons to the electrons is decreasing.