Researchers argue that some bacteria found in the human gut are in a symbiotic relationship with humans, called mutualism. Which of the following observations is consistent with this argument?

Bacteria increase te risk of cancer in humans.

Explanation:

When two species benefit from each other, the symbiosis is called mutualism (or syntropy, or crossfeeding). For example, humans have a mutualistic relationship with the bacterium Bacteroides thetaiotetraiotamicron, which lives in the intestinal tract.

the answer is d (apex) good luck : ))