ACTIVITY IMMEDIATE PREDECESSOR$($S$)$ NORMAL TIME $($NT$)$ CRASH TIME $($CT$)$ NORMAL COST $($NC$)$ CRASH COST $($CC$)$

A $85$ $$8$ $$32$

B A $41$ $$2$ $$5$

C A $75$ $$5$ $$15$

D A $86$ $$5$ $$9$

E B$,$ C$,$ D $33$ $$10$ $$10$

a$.$ If you want to crash one week, what activity$/$activities should be crashed? If multiple activities need to be crashed simultaneously, enter them in uppercase and in alphabetical order with a space between them, for example, A B$,$ not AB$,$ B A$,$ A$-$B$,$ etc.