Overhead service conductors of a 120/240-volt service are run above a roof with a slope of 6:12, and the roof is not an overhanging roof. The minimum required clearance from the roof is not an overhanging roof. The minimum required clearance from the roof to the overhead service conductors that are above the roof is ____ ft.
a) 3
b) 4.5
c) 6
d) 8