[单选题]
Which of the following is equivalen*dt x n )lg j3(fsx6,xopzza-9t to thm j6d1f:b4p jae c8 3 dd:xsdv 6qgy.i3cq24tbe unit of electric potential differencedq63d6stj 3:b.c1iab 4x8m42 v dcepjq d: ygf?
A. $NmC ^{−1}$
B. $Nm^{−1}C^{−1}$
C. $JC$
D. $Jm^{−1}C^{−1}$
