A Proton and an Electron Are Accelerated Until Their Total

Multiple Choice

A proton and an electron are accelerated until their total energy is twice their rest masses.If the rest mass of the proton is M_pc² = 931 MeV and that of the electron is M_ec² = 0.51 MeV,the ratio of the velocity of the electron to that of the proton is

A) 0.5
B) 1.0
C) 1.5
D) 2.0
E) not enough data are given