JEE Main 2020 Physics question

If the screw on a screw-gauge is given six rotations, it moves by 3 mm on the main scale. If there are 50 divisions on the circular scale the least count of the screw gauge is-

• (A)0.001 cmCorrect
• (B)0.02 mm
• (C)0.01 cm
• (D)0.001 mm