The correct answer is D.
OBJ-3.2.3: The role represents the interests of all those who will use the project product, those for whom the product will achieve an objective or those who will use the product to deliver benefits. The user representative role commits user resources and monitors products against requirements. For the sake of effectiveness, the role should not be split between too many people. The user representative is responsible for specifying the needs of those (including operations and maintenance services) who will use the project product for user liaison with the project management team and for monitoring that the solution will meet those needs within the constraints of the business case in terms of quality, functionality, and ease of use.