A subcontractor fails to complete their scope of work on a project. The prime contractor's primary recourse is:

Explanation

When a subcontractor defaults, the prime's contract remedy is to terminate that subcontract, have the scope finished by others, and recover the difference from the defaulting sub — or from its performance bond, if one was furnished. (a) CSLB discipline can suspend or revoke the sub's license, but the Registrar has no power to order the work completed or to make the prime whole; that is a court's or an arbitrator's job. (d) A change order moves the cost onto the owner, who neither caused the default nor agreed to pay twice for the same scope. (c) Walking off is worse than useless: abandoning a project without legal excuse is itself cause for discipline under B&P §7107, so the prime would trade a collection claim for a license problem.