A software development project is based on the following:

Activity Predecessor Successor Normal

Time Normal

Cost Crash

Time Crash

Cost

A $$ C $8$ $ $2007$ $ $300$

B $$ D $103006400$

C A E $280011000$

D B E $42002300$

E C$,$ D $1550011800$

The project manager determines it is necessary to shorten the completion time for the project.

a$.$ If she decides to crash the project by one day, what activity should be crashed?

multiple choice $1$

Activity A

Activity B

Activity D

Activity E

b$.$ What is the total project cost after crashing by one day?

c$.$ If she decides to crash by two days, what activity should be crashed next?

multiple choice $2$

Activity A

Activity B

Activity D

Activity E

d$.$ What is the total project cost after crashing by two days?