In this model, four relationships are described only by their stated effect on each species. Which one is mutualism?
Species A gains food and species B is killed and eaten
Species A gains shelter and species B is neither helped nor harmed
Species A gains food and species B gains protection from its predators✓الإجابة الصحيحة
Species A gains food and species B is weakened over time but survives
الشرح
Mutualism requires a benefit on both sides, and only the pairing in which one species gains food while the other gains protection describes a gain for both. The relationship where one gains shelter and the other is unaffected fails, because that is commensalism and gives the second species no benefit.