The remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
Mold fossils
Cast fossils
Trace fossils

In humans, the medulla region of the brain is mainly responsible for the regulation process of respiration. It is also called the respiratory rhythm centre. The chemosensitive area located near the respiratory centre sends signals across nerve impulses to alter the rate of expiration to eliminate compounds.
Answer:
D. more, faster
Explanation:
The more surface area exposed the faster the weathering occurs.