Which of the following is the correct ohm's law formula? a. i = r/e b. r = i/e c. i = e/r d. p = ei

We know that
The Ohm's law formula states that
The resistor's current I in amps (A) is equal to the resistor's voltage V in volts (V) divided by the resistance R in ohms (Ω):
so
I=V/R
In some cases, Ohm's law uses the letter E to represent voltage. E denotes electromotive force
I=E/R

therefore

the answer is the option 
C.) I = E/R