To convey a longitude of 15 degrees 45 minutes, what signal would you use?

The correct signal for conveying a longitude of 15 degrees 45 minutes is G1545. This is because maritime signal codes often use specific letters to represent different geographical coordinates. In this syntax, the letter "G" is used to signify longitude, particularly in the context of navigational practices.

Each letter corresponds to a specific type of information. For example, in maritime communications and signal flags, "G" is recognized as the designation for a geographic location along the lines of longitude. The number that follows the letter indicates the specific degrees and minutes. Therefore, G1545 accurately communicates the longitude of 15 degrees 45 minutes.

The other choices do not use the correct designation letter for longitude, making them unsuitable for this purpose. For instance, "L," "X," and "D" do not correspond to the conventional maritime signaling used for longitude in this case. Thus, G1545 is the appropriate choice for representing that particular longitude.