In project management, what is true about an activity, that has the following characteristics:

Earliest start $($ES$)=2$

Earliest finish $($EF$)=6$

Latest start $($LS$)=2$

Latest finish $($LF$)=6$

Group of answer choices

this activity has a duration $($time to complete$)$ of $4$

this activity is not on the critical path

this activity has a slack of $4$

this activity has a duration $($time to complete$)$ of $6$