$\backslash$table$[[$Activity$,$Designation,Predecessor,Time in Days$],[$Break down both machines,A$,$None,$3],[$Clean machine $1,$B$,$A$,2],[$Clean machine $2,$C$,$A$,4],[$Re$-$set machine $1,$D$,$B$,3],[$Re$-$set machine $2,$E$,$C$,2],[$Re$-$calibrate both machines,F$,$D and E$,2],[$Final test,G$,$F$,4]]$

Using the Single Time Estimate CPM procedure, what is the slack time of Task E$?$

$0$

$1$

$2$

$3$

$4$