What is the potential downside to bringing project workers into a project too early?

a$.$ People don't like being told what to do$,$ but are usually enthusiastic if they can participate in creating the project plan.

b$.$ When the people who perform the work help to plan it$,$ many more details may be considered.

c$.$ People may still be committed to finishing work on a previous project.

d$.$ For external projects, it is common to list the specific workers who will be assigned to a project team in the proposal.