Consider the following project:

Activity A$,$ Duration $3,$ Predecessor None

Activity B$,$ Duration $6$ days, Predecessor A

Activity C$,$ Duration $3$ days, Predecessor A

Activity D$,$ Duration $3$ days, Predecessors B$,$ C

Activity E$,$ Duration $4$ days, Predecessor D

Activity F$,$ Duration $6$ days, Predecessor D

Which of the following activities would not to shorten the project calendar length by crashing?

Question $7$Select one:

a$.$

B

b$.$

D

c$.$

None of these answers is correct

d$.$

C

e$.$

A