正解:D
According to the BABOK Guide, a requirement is a usable representation of a need that specifies what a stakeholder requires from a solution. A requirement must be verifiable, which means that it can be tested, validated, or confirmed by some objective means. If a requirement cannot be verified, it cannot be successfully implemented, because there is no way to ensure that the solution meets the requirement and delivers the expected value. Reference: BABOK Guide, page 10; Business Analysis Expert Certification, CCBA| IIBA, section "What Should I know to be CCBA Certified?"