Question

radon seeps out of the ground. where is it most likely to accumulate in homes? basements attics

Explanation:

Radon is a gas that is denser than air. Since basements are lower - level areas of homes and are closer to the ground where radon seeps out, and being denser than air, radon will tend to sink and accumulate in lower - lying areas like basements rather than attics (which are upper - level areas).

Answer:

A. Basements