The pitch and the number of divisions on the circular scale for a given screw gauge are 0.5 mm and 100 respectively. When the screw gauge is fully tightened without any object, the zero of its circular scale lies 3 divisions below the mean line. The readings of the main scale and the circular scale for a thin sheet are 5.5 mm and 48 respectively. The thickness of the sheet is:
a. 5.755 mm
b. 5.950 mm
c. 5.725 mm
d. 5.740 mm