An Electron, Initially at Rest, Is Accelerated Through a Potential $5.4 \times 10 ^ { - 30 } \mathrm {~kg}$

Multiple Choice

An electron, initially at rest, is accelerated through a potential difference of 2.5 MeV, thereby increasing its total energy by 2.5 MeV. The mass of the electron is

A) $5.4 \times 10 ^ { - 30 } \mathrm {~kg}$
B) $9.1 \times 10 ^ { - 31 } \mathrm {~kg}$
C) $4.5 \times 10 ^ { - 30 } \mathrm {~kg}$
D) $4.5 \times 10 ^ { - 31 } \mathrm {~kg}$