How is 12:00 AM represented in 24-hour time format?

In 24-hour time format, midnight is represented as 0000. This format eliminates the need for "AM" and "PM" designations, which simplifies timekeeping. The first hour of the day starts at 00:00 (midnight) and runs through 23:59 until the next midnight. Therefore, 0000 indicates the very beginning of the day, providing a clear, unambiguous reference to midnight.

The other options misrepresent midnight in various ways. For example, while 2400 might seem intuitive for midnight in some contexts, it is not standard practice to use this representation in military or formal timekeeping. Instead, 2400 is often contingent upon the context of the end of the day. The representation of 1200 refers to noon, when the sun is at its highest point. The option of 2200 indicates 10:00 PM, which is clearly not related to midnight. Each of these alternatives highlights different points in the day rather than the midnight hour itself.