Final answer:
d) Domestic or international waters, or both. Warning areas are defined dimensions of airspace that may be hazardous to nonparticipating aircraft. They serve to warn pilots of potential danger and can be located over domestic or international waters.
Step-by-step explanation:
Warning areas are defined dimensions of airspace that extend from 3 NM outward from the coast of the United States. These areas contain activity that may be hazardous to nonparticipating aircraft and serve the purpose of warning nonparticipating pilots of potential danger. Warning areas can be located over domestic or international waters, or both.