Potential difference and power — practice question

Which unit is equal to the unit of electric field strength?

• A$\text{J C}^{-1} \text{m}^{-1}$
• B$\text{N s A}^{-1}$
• C$\text{kg m s}^{-3} \text{A}^{-1}$
• D$\text{kg m}^3 \text{s}^{-3} \text{A}^{-1}$