Question

what happened to the arctic ocean during the past 40 years? (1 point)
it has become warmer
it has become cooler
it has grown smaller
it has gained more sea ice.

Explanation:

Due to global - warming, the Arctic Ocean has experienced a rise in temperature over the past 40 years. Sea ice has been decreasing, not increasing, and there is no indication it has grown smaller in size in terms of surface area in the context of the main environmental changes. Cooling is not the trend.

Answer:

It has become warmer