Answer:
A carcinogen can be described as any substance which can lead to cancer.
Various types of pollution produce certain kinds of ions such as metal ions which are capable of producing cancer in humans.
Studies have shown that toxic metals from waste when disposed in lakes from industries or plant areas causes the toxic metals to get accumulated in the bodies of water animals such as the fishes. These organisms when consumed by humans can cause cancer.
A few carbohydrates include sugars, starches and fibers.
Answer: A
