What Is the Total Energy of an Electron Moving with a Speed

Multiple Choice

What is the total energy of an electron moving with a speed of $0.950 c ? \left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } , m _ { e l } = 9.11 \right.$ $\times 10 ^ { - 31 } \mathrm {~kg}$ )

A) $2.6 \times 10 ^ { - 13 } \mathrm {~J}$
B) $8.2 \times 10 ^ { - 14 } \mathrm {~J}$
C) $1.2 \times 10 ^ { - 14 } \mathrm {~J}$
D) $1.1 \times 10 ^ { - 13 } \mathrm {~J}$