A task needs to be completed by a specific date, so the Project Manager manually selects the Planned Completed Date. Which task constraint does this apply to the task?

When a Project Manager manually selects the Planned Completed Date for a task, this specifically indicates that the task must be completed by that date, thus applying a "Must Finish On" constraint. This constraint is crucial when there are dependencies or project deadlines that necessitate the completion of the task by a defined date. Setting this type of constraint highlights the task's critical nature in the overall project timeline, ensuring that it does not extend beyond the specified date.

This choice stands apart from others like "Finish no earlier than," which allows for flexibility in completing the task as long as it does not finish before a certain date, or "As Late As Possible," which pushes the task to the maximum allowable time frame without affecting subsequent tasks. The "Deadline" option also implies a sense of urgency, but it typically does not enforce the same level of certainty as "Must Finish On." It may allow for some leeway, thus not representing the strict completion requirement associated with a specifically chosen Planned Completed Date.