Numerical Problems. Mark the right answer. One way to do it is to make the answer $($just a$,$ b$,$ or so forth, not the entire sentence$)$ boldface. Each question carries $8($eight$)$ points.

$1.$ A simple project listing of five activities and their respective time estimates are presented below:

Activity Immediate Predecessor Time in Days

A None $1$

B A $2$

C A $1$

D B and C $3$

E D $2$

Which activities make up the critical path?

A$.$ A$,$ C$,$ D$,$ E

B$.$ A$,$ B$,$ D$,$ E

C$.$ A$,$ C$,$ B$,$ D$,$ E

D$.$ A$,$ D$,$ E

E$.$ None of the above