While transporting a self$-$propelled power shovel to a job site on a company$-$owned flatbed truck, an employee of IRTH Movers, Inc., an excavation contractor, fails to notice a low clearance sign and the boom of the shovel clips an overpass. The resulting claim against IRTH for damage to the overpass is

a$.$ covered under IRTH's CGL due to an exception to the mobile equipment exclusion.

b$.$ covered under IRTH's CGL$,$ subject to the auto liability sublimit.

c$.$ excluded under IRTH's CGL due to the mobile equipment exclusion.

d$.$ covered under IRTH's CGL due to an exception to the auto exclusion.