The scale of a galvanometer of resistance `100 ohms` contains 25 divisions. It gives a defelction of one division on passing a current of `4xx 10 ^(-4)` amperes. The resistance in ohms to be added to it, so that it may become a voltmeter of range `2.5` volts is
A. 100
B. 150
C. 250
D. 300