A 1,300-N/C Electric Field (In a Vacuum) Has an Energy $5.1 \times 10 ^ { - 5 } \mathrm {~J} / \mathrm { m } ^ { 3 } \text {. }$

A 1,300-N/C electric field (in a vacuum) has an energy density of

A) $5.1 \times 10 ^ { - 5 } \mathrm {~J} / \mathrm { m } ^ { 3 } \text {. }$
B) $6.3 \times 10 ^ { - 7 } \mathrm {~J} / \mathrm { m } ^ { 3 }$
C) $9.5 \times 10 ^ { - 5 } \mathrm {~J} / \mathrm { m } ^ { 3 }$
D) $7.5 \times 10 ^ { - 6 } \mathrm {~J} / \mathrm { m } ^ { 3 }$