Two batteries of `E_(1)` internal resistance `r_(1)` & emf `E_(2)` internal resistance `r_(2)` are connected in parallel and makes a battery system. An external resistance R is connected across this system as shown in the figure.

Options

A. if `R` is infinite the equivalent emf of system across A and B is `(E_(1)r_(1)+E_(2)r_(2))/(r_(1)+r_(2))`
B. if `R` is infinite the equivalent emf of system across A and B is `(E_(1)r_(2)+E_(2)r_(1))/(r_(1)+r_(2))`
C. The current in external circuit is given as `((E_(1)r_(2)+E_(2)r_(2))/(r_(1)+r_(2)))/(R+(r_(2)r_(1))/(r_(2)+r_(1)))`
D. The current in external circuit is given as `((E_(1))/(r_(1))+(E_(2))/(r_(2)))/(1+(R)/(r_(1))+(R)/(r_(2)))`