Which of the following is a zero time activity?

A milestone is a significant point or event in a project schedule, often used to mark the completion of a major phase, deliverable, or set of activities. By definition, a milestone has zero duration, as it represents an instantaneous point in time rather than an activity that consumes time.

The critical path is a sequence of activities that determines the shortest possible duration to complete the project, and its activities inherently have duration.

A deliverable is a tangible or intangible output of the project that results from activities, and the creation of a deliverable typically involves time-consuming work.

A work package is a small, manageable component of a project, consisting of defined work activities that consume time and resources to complete.