The project calendar needs to be updated to reflect the 24-hour time period rather than the 8-hour time period. The project calendar is used to define the working and nonworking days and times for tasks. This calendar is usually used to represent an organization's traditional working hours. Project uses this calendar to schedule tasks that do not have resources assigned or that have a task type of fixed duration. By default, the Standard base calendar is used as the project calendar. A user can also reflect alternative schedules by using other base calendars. The working days and hours in the project calendar reflect the working days and hours for the whole project. A user can also specify special days off, such as company holidays. A user can also indicate other nonworking times to reflect periods when the whole team will be working on nonproject activities, such as company meetings or department retreats.

Answer option D is incorrect. The schedule management plan will reference to the project calendar and the resource calendar. It does not need to be updated directly as a result of the time period change.

Answer option C is incorrect. The resource calendar does not need to be updated as this document defines when resources are available.

Answer option B is incorrect. The activities of the project are not changing, only the time periods of the project calendar.