The Potential Energy for the Formation of a Hydrogen Molecule

The potential energy for the formation of a hydrogen molecule can be approximated by U = -A + BR + C/R, where R is the nuclear separation. Given that A = -78.5 eV, B = 2.57 × 10¹¹ eV/m , and C = 1.44 × 10^-9 eV∙m. At what nuclear separation is the potential energy a minimum?

A) 1.9 × 10^-11 m
B) 3.7 × 10^-10 m
C) 7.5 × 10^-11 m
D) 2.9 × 10^-11 m
E) 5.1 × 10^-10 m