A vernier callipers having `1` main scale division `= 0.1 cm` to have a least count of `0.02 cm`.If `n` be the number of divisions on vernier scale and `m` be the length of vernier scale, then.
A. n = 10,m = 0.5 cm
B. n =9,m = 0.4 cm
C. n = 10,m = 0.8 cm
D. n = 10,m = 0.2 cm