mutualism commensalism parasitism phototropism
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A plover bird eats bits of food that become stuck in a crocodile's teeth without being hurt. The crocodile gets its teeth cleaned and the bird gets food. Which type of relationship exists between the bird and the crocodile?
Possibilities:
- mutualism
- commensalism
- parasitism
- phototropism

mutualism