If you sent out a signal on 12 March 1980, how would the date be indicated?

The correct way to represent the date March 12, 1980, in the specified format is D120380. This format follows a convention where the letter 'D' indicates the type of signal, followed by the date in a specific sequence.

In this case, the '12' represents the day, '03' signifies the month of March, and '80' indicates the year 1980. This structured approach ensures clarity and allows for immediate recognition of the date by anyone familiar with this format.

This method of encoding dates is particularly useful in maritime communication, where clarity and brevity are essential for effective information relay. The other formats provided do not conform to this established format, leading to potential confusion or misinterpretation of the date.