Which of the following is false?

If an activity has a slack value greater than zero, it needs to be a critical activity

If Activity A needs to be completed before Activity B starts, Activity A is the immediate predecessor of activity $B$

Lateness in activities, which are not located on the critical path, may or may not result in lateness in overall project completion time, depending on their slack time

Lateness in any of the activities located on the critical path would result in lateness in overall project completion time

If there is only one activity in a project, it needs to be a critical activity