A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it ?

Options

A. A meter scale
B. A vernier callipers where the 10 divisions in vernier scale match with 9 divisions in main scale and main scale has 10 divisions in 1 cm.
C. A screw gauge having 100 divisions in the circular scale and pitch as 1 mm.
D. A screw gauge having 50 divisions in the circular scale and pitch as 1 mm.