The correct option is C 00:45
Time between 12:00 A.M. to 12:59 A.M. can be converted to 24-hour format by subtracting 12 hours.
∴ 12:45 A.M. in 24-hour format
= 12:45 A.M. - 12 hours
= 12 hours + 45 minutes - 12 hours
= 45 minutes = 00:45
Therefore, (c) is the correct option.