Final answer:
Garbage disposal at sea is regulated by MARPOL, and plastics cannot be disposed of within 200 nautical miles from the coast. For other types of garbage, strict rules apply within this zone.
Step-by-step explanation:
The specific distance from any coastline that garbage can be thrown overboard is regulated by international laws to prevent pollution of the marine environment. According to the International Convention for the Prevention of Pollution from Ships (MARPOL), the disposal of garbage into the sea is highly regulated and in most cases prohibited unless done at a significant distance from the coast. The correct answer is d) 200 nautical miles. Within this distance, the disposal of plastics is completely forbidden, and other types of garbage may only be disposed of under strict regulations.