Which best explains why a general contractor requires each subcontractor to carry its OWN workers' compensation insurance?

解析

If a subcontractor has no workers' compensation coverage, its injured workers can be treated as employees of the hiring contractor, whose own policy then pays and whose experience rating carries the loss. Requiring each sub to insure its own people keeps that exposure where it belongs. (a) overstates the licensing rule: under B&P §7125(b) a licensee with no employees may still file an exemption unless it holds one of the excluded classifications. (c) is false — a contractor's policy covers its own construction employees. (d) mixes workers' compensation with the lien statute, which says nothing about it.