Convert 3:00 PM to 24-hour time format.

To convert 3:00 PM into 24-hour time format, you start by understanding how time is represented in that system. In the 24-hour format, hours from midnight to noon remain the same, while hours from noon to midnight are adjusted by adding 12 to the hour.

3:00 PM is in the afternoon, and in the 24-hour format, you add 12 to the hour. Thus, you take the hour 3 and add 12, resulting in 15. The minutes remain unchanged at 00.

Therefore, 3:00 PM in 24-hour time is written as 1500. This makes option B the correct answer.