The approval by the Architecture Review Board is a milestone you want to include in activity sequencing so that you can ensure the requirements for meeting the review board's approval are met.  Answer A is tempting because the question references phase-end activities; however, it is not an example of gatekeeping because the project is not being authorized to continue based only on the architecture review.Gatekeeping often involves the review of other factors as well. Answer C is incorect because the requirement of a review board approval does not afect scope. Answer D is incorrect because project integration planning involves project plan development, execution, and integrated change control, which are not related to a review board.

Answer A is tempting because the problem focuses on changes. However, because we are talking about the elaboration of the product's characteristics, we are talking about scope changes, and therefore Answer B is the best answer. Answer C is also tempting because it is difficult to more forward on a project until the scope is clearly defined (especially in systems development projects), but with products and certain types of web development, scope changes can be frequent, and a formal scope management plan is needed. Answer D is true from a project perspective, but does not addres the scope issues.

Project authorization should not be exclusively based upon the impact of an executive's bonus (many people would agree that it should not ever be based upon an executive's bonus). Answer A, B, and D are common events that predicate the need for project authorization and can evolve into large scope projects.

The other answers could be accurate in specific situations, but their role alone does not meet the keyb criterion of being "external" to the project team. Answers A, B, and D are incorrect because these individuals are not external to the project.

Corrective actions are part of the process after establishing objectives and checking on the objectives. The next step is to take corrective actions. Answers A, C, D are true statements and therfore are incorrect for this question.

Answer A is incorrect because without satisfied customers, we do not have potential for new projects. Answer C is incorrect because the change control management process would have likely resolved this problem. Answer D is incorrect because it is the project manager's responsibility to seek communication with the customer to set realistic expectations.