BOTH INTERNATIONAL & INLAND A "flashing light" is a light that __________.

Correct Answer: Option C — flashes at regular intervals at a frequency of 120 flashes or more per minute

COLREG Rule 33 defines a flashing light as a rhythmic light flashing at regular intervals at a frequency of 120 flashes or more per minute, commonly utilized for special-purpose vessels like air-cushion vessels or submarines.