Question

what types of benefits would result if we implemented a solution that could prevent even half of the polar ice melt and sea level rise that would otherwise happen?
all of the above.
fewer people who live near coasts would have to move.
some polar ecosystems would be preserved.
some coastal environments would be protected.

Explanation:

Preventing half of polar ice - melt and sea - level rise would reduce displacement of coastal residents, preserve polar ecosystems, and protect coastal environments.

Answer:

A. All of the above.