A certificate of insurance shows a policy in force for a full year, but the insurer cancelled that policy the following week. The holder's coverage is:

解析

A certificate of insurance is evidence of what was in force on the day it was issued; it is not part of the policy, it does not bind the insurer, and its own text usually says so. If the policy was properly cancelled, there is no coverage whatever dates the certificate carries. (c) is the 30-day notice-of-cancellation term that appears in contracts and in some endorsements — a promise to tell the holder that coverage is ending, not a promise of 30 more days of it, and not a rule of law. (a) is the certificate-as-contract error. (d) confuses the holder's own program with the contractor's; nothing transfers between policies.