a$.$ Choose the correct network diagram below.

$$ A$.$

B$.$

$$

c$.$ D$.$

$$

b$.$ Calculate the slack for each activity. Which activities are on the critical path?

$\backslash$table$[[$Activity$,$Activity Time $($weeks$),$On critical path?,Slack $($weeks$)],[$A$,4,$V$,],[$B$,7,$v$,],[$C$,7,$grad,$],[$D$,11,$grad,$],[$E$,10,$grad,$$