In a Simple Picture of the Hydrogen Atom,the Electron Moves $\times$

Multiple Choice

In a simple picture of the hydrogen atom,the electron moves in circular orbits around the central proton attracted by the Coulomb force.The lowest (n = 1) energy orbit that is allowed for the electron is at a radius of 5.29 $\times$ 10^-11 m and the second (n = 2) lowest allowed orbit is at 4 times this radius.How many times stronger is the magnetic field strength at the proton due to the orbital motion of the electron in the n = 1 state than the n = 2 state?

A) 64
B) 16
C) 4
D) 1
E) 32