(a)      Calvert County and St. Mary's County may provide, by resolution, a tax exemption for classes of hotels.

      (b)      In Frederick County, the hotel rental tax does not apply to a hotel with 10 or fewer sleeping rooms in its main building and no more than 20 additional sleeping rooms in auxiliary structures on the hotel's property.

      (c)      In Washington County, the hotel rental tax does not apply to a transient charge paid to a hotel by:

            (1)      The federal government;

            (2)      A state; or

            (3)      An agency or instrumentality of a state or of the federal government.

      (d)      In Carroll County, the hotel rental tax does not apply to a hotel with 10 or fewer sleeping rooms.