- A One benefits, one is harmed
- B Both organisms benefit
- C One benefits, other is unaffected
- D Neither benefits
Correct answer: B. Both organisms benefit
Explanation: Mutualism: both species benefit (e.g., bees and flowers, cleaner fish and sharks, Rhizobium and legumes).
Concept context
Ecosystems, food chains, energy flow, nutrient cycles, biodiversity, and conservation.