$\backslash$table$[[,,,,,],[,\backslash$table$[[$Activity$,$Normal$\_$time,Crash$\_$time,Normal$\_$cost Crash$\_$costSlach$,],[$A$,33,21,4900,6300]],$Activity Normal$\_$time Crash$\_$time Normal$\_$cost Crash$\_$cost Slack,,$],[,,,,,],[\backslash$table$[[$B$,21,21,4700,4700,0],[$C$,15,12,4000,6700,0]],,],[$D$,,25,4300,4300,1],[$E$,,,5600,5600,0],[$F$,33,24,5400,6900,1]]$

The table shows normal time $($in days$),$ crash time $($in days$),$ nhrmal cost $($in dollars$),$ crash cost $($in dollars$)$ and slack time $($in days$)$ of activities in a small construction project. According to this table which activity must be crashed first? Assume there is only one critical path. $($Only type the name of the activity, Example: A$.$ @orsdemir. Copyrighted content. Cannot be posted.$)$