Question

which definition describes endosymbiosis best?
○ a symbiotic relationship in which one organism lives on the other organism and both organisms benefit
○ a symbiotic relationship in which one organism lives inside the other and both organisms benefit
○ a symbiotic relationship in which one organism benefits, while the other organism is harmed
done

Explanation:

Endosymbiosis is a symbiotic relationship where one organism lives inside another, and both benefit. The first option says "on" (not inside), the third is parasitism (one harmed). So the second option matches.

Answer:

B. a symbiotic relationship in which one organism lives inside the other and both organisms benefit (assuming the second option is labeled B; adjust label as per original question's numbering if different)