A project for improving a billing process has the following precedence relationships and activity times.

$\backslash$table$[[$Activity$,$Activity Time $($weeks$),$Immediate Predecessor$($s$)],[$A$,5,-],[$B$,7,-],[$C$,5,$A$],[$D$,12,$B$,$ C$],[$E$,9,$B$],[$F$,5,$D$],[$G$,3,$E$],[$H$,9,$F$,$ G$]]$

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$,\backslash$table$[[$Activity$],[$Time $($weeks$)]],\backslash$table$[[$On$],[$critical path?$]],\backslash$table$[[$Slack$],[($weeks$)]]],[$A$,5,$V$,],[$B$,7,,],[$C$,5,,],[$D$,12,,],[$E$,9,,],[$F$,5,,],[$G$,3,,],[$H$,9,,]]$