Convert the given class intervals in exclusive form.

The correct option is B
Here the class intervals are given in the inclusive form. In order to convert it in the exclusive form, we need to use the adjustment factor.

Adjustment factor = $\frac{1}{2}$ (the difference between the upper limit of a class and the lower limit of the next class)

Here we subtract the calculated adjustment factor from all the lower limits and add it to all the upper limits.

50.5 - 60.5
60.5 - 70.5
70.5 - 80.5
80.5 - 90.5
90.5 - 100.5