AssertionA: If in five complete rotations of the circular scale,...

$AssertionA:$ If in five complete rotations of the circular scale, the distance travelled on the main scale of the screw gauge is $5mm$ and there are $50$ total divisions on a circular scale, then the least count is $0 . 001cm .$

$ReasonR:$
Least Count $= \dfrac{\text{Pitch}}{\text{Total divisions on circular scale}}$
In the light of the above statements, choose the most appropriate answer from the options given below.