Consider the following table of activities that describes a project network. Which activity will you crash second?

Project Activities

Activity

Predecessors

Normal

duration

$($days$)$

Crash

duration

$($days$)$

Normal cost

Crash cost

A

$--$

$10$

$5$

$

$1,000$

$

$3,000$

B

A

$20$

$10$

$

$4,000$

$

$6,000$

C

A

$5$

$4$

$

$2,000$

$

$4,000$

D

B$,$ C

$3$

$2$

$

$1,000$

$

$2,000$

E

B$,$ C

$20$

$10$

$

$5,000$

$

$10,000$

F

B$,$ C

$4$

$3$

$

$3,000$

$

$4,000$

G

D$,$ E$,$ F

$10$

$5$

$

$2,000$

$

$5,000$