A
Explanation:
The answer is 24 calender months
Before being able to act as pilot in command a pilot must have completed a flight review within the previous 24 calendar months. This is known as a biennial flight review is a review required of every active holder of a U.S. pilot certificate at least every 24 calendar months. The instructors let you know that it is not a test. There are no pass or fail criteria, although the instructor giving it can decline to endorse your log-book that a flight review has been completed.[