A resistor of resistance R R\,R and four identical cells of emf E E\,E and internal resistance r r\,r are connected as shown.

What is the current in the resistor?
4E4R+r\frac{4E}{4R + r}4R+r4E
16E4R+r\frac{16E}{4R + r}4R+r16E
ER\frac{E}{R}RE
4ER\frac{4E}{R}R4E