The correct answer is A) AAA. The International Code of Signals specifies that the signal AAA is used to indicate a decimal point between figures when using flashing light. This is the standard convention for communicating decimal points in Morse code or flashing light signals, as per the established regulations and guidelines for maritime signaling. The other answer choices are incorrect because they do not correspond to the established standard for representing a decimal point in flashing light signals. B) AS, C) EEEEE, and D) TTTT are not the correct International Code signals for this purpose.