A project manager will conduct a release on the third Friday of the month.

Application deployment typically involves making a software application available for use, often involving downtime or unavailability of the application. The description of the project manager notifying users about the application being unavailable for a certain period aligns with standard practices during deployment phases. The other options, such as rollback plans, validation checks, and maintenance window schedules, although important, do not directly indicate the action of making an application available for use, as described in the scenario.