A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it ?
A. A vermier calliper where the 10 divisions in vernier scale matches with 9 division in main scale and main scale has 10 divisions in 1 cm
B. A screw gausge having 100 divisions in the circular scale and pitch as 1 mm
C. A meter scale
D. A screw gauge have 50 divisions in the circular scale and pitch as 1 mm