in a network$$ diagram, an activity

Part $2$

A$.$

is the smallest unit of work effort consuming both time and resources that a project manager can schedule and control.

B$.$

is the largest unit of work effort consuming both time and resources that a project manager can schedule and control.

C$.$

must always have a$$ single, precise estimate for the time duration.

D$.$

should always be something the company has had experience with.