The alvin was used to recover a nuclear bomb study ocean currents gather data on the arctic ice cap observe marine life in the challenger deep

Option (2)

Explanation:

The Alvin is a human-made vehicle that helps to dive deep into the oceans in order to study the ocean currents and the vertical distribution of water. It is also helpful in constructing maps and ocean floor topographic surveys. It is so technically designed that the humans diving with this vehicle at a greater depth, below the water can withstand the extreme pressure.

It is the first deep-ocean submersible craft in the whole world that is constructed in order to research and explore the ocean.

Hence, the correct answer is option (2).

geologic time scale (for gradpoint) =)