A galvanometer, whose resistance is 50 ohm, has 25 divisions in it. When a current of 4×10−4 A passes through it, its needle (pointer) deflects by one division. To use this galvanometer as a voltmeter of range 2.5 V, it should be connected to a resistance of :
a. 250 ohm
b. 200 ohm
c. 6200 ohm
d. 6250 ohm