(C.T.9.3) 16. Four resistors are connected as shown in the figure. It is found that the current

16. Four resistors are connected as shown in the figure. It is found that the current flowing through the galvanometer G is zero. The resistance of R is
(Α) 3 Ω
(Β) 4.5 Ω
(C) 18 Ω
(D) impossible to determine without knowing the e.m.f. of the battery.