The correct answer is option 1, the Pacific Ocean. The "Ring of Fire" is a geological term used to describe a major area in the basin of the Pacific Ocean where a large number of earthquakes and volcanic eruptions occur.

Option 2, the Atlantic Ocean, is incorrect because the "Ring of Fire" is not found along the margins of the Atlantic Ocean. The Atlantic Ocean is more known for its mid-Atlantic ridge system, which is an underwater mountain range.

Option 3, the Indian Ocean, is also incorrect. Though there are active tectonic plate boundaries in the Indian Ocean, the "Ring of Fire" is not primarily associated with this region.

Option 4, the Mediterranean Sea, is also incorrect. While the Mediterranean region does have active tectonic activity due to the collision of the African and Eurasian plates, it is not considered part of the "Ring of Fire."

In summary, the correct answer is option 1 because the "Ring of Fire" is found along the margins of the Pacific Ocean, where it is home to a significant amount of seismic and volcanic activity.