ACMP explains thatproject managementfocuses on delivering outputs (scope, schedule, budget, quality), whereaschange managementfocuses on ensuring adoption, usage, and benefits realization by addressing the people side of change. This difference infocusis the clearest and most fundamental distinction. While differences in plans, stakeholders, and levels of focus exist, option A captures the primary clarification needed: methodologies differ infocus and objectives.
(Reference: ACMP Standard, Introduction; Distinction between project management outputs and change management outcomes.)