Correct Answer - C
Given, two cells of emf `E_(1)` and `E_(2)` are joined in opposition such that, `E_(1)gt E_(2)`.
Current, `l=(E_(1)-E_(2))/(r_(1)+r_(2)+R)`
Now, terminal potential difference across a circuit,
`V=lR=((E_(1)-E_(2))/(r_(1)+r_(2)+R))R`