Question $2(1$ point$)$

A simple CPM network has three activities, D$,$ E$,$ and F$.$ D is an immediate predecessor of $E$ and of $F.E$ is an immediate predecessor of $F.$ The activity durations are $D=5,E=4,F=9.$

The critical path is D$-$F$,$ duration $14.$

The critical path is D$-$E$-$F$,$ duration $18.$

Slack at $E$ is $4$ units.

The network has two critical paths.

Slack at D is $4$ units.