The rest mass of a proton is \({\text{938 MeV}}\,{{\text{c}}^{ - 2}}\). The energy of a proton at rest is

A.     \(9.38{\text{ J}}\)

B.     \(9.38 \times {10^8} \times {(3 \times {10^8})^2}{\text{ J}}\)

C.     \(9.38 \times {10^8}{\text{ eV}}\)

D.     \(9.38 \times {10^8} \times {(3 \times {10^8})^2}{\text{ eV}}\)

C

Many candidates appeared unfamiliar with the unit \({\text{MeV}}\,{{\text{c}}^{ - 2}}\), despite the fact that the Physics Guide states that students should be familiar with this unit.