Find the activities that are on the critical path for completing the project in the shortest time.

Question $13$ options:

a$)$

P$1-$P$2-$P$3-$P$4-$S$2-$V$1-$V$2$

b$)$

P$1-$P$2-$P$3-$P$4-$S$1-$D$2-$D$4-$I$1-$I$4-$V$2$

c$)$

P$1-$P$2-$P$3-$P$4-$S$1-$D$1-$D$4-$I$1-$I$4-$V$2$

d$)$

P$1-$P$2-$P$3-$P$4-$S$1-$D$3-$D$4-$I$1-$I$4-$V$2$