The project manager and the core team need to determine who will make which types of project decisions. Some may be made by the sponsor, functional manager, core team, etc. Which of these is NOT a valid guide to decision making on projects?

a$.$ Sponsor decides to ensure buy$-$in from all participants.

b$.$ Core team discusses and project manager decides, because team input is useful.

c$.$ Decision is delegated to one or two team members to decide, because team input not needed.

d$.$ Functional manager decides, "how" functional work on the project is done.