17. Which statement best represents the MAIN IDEA of the article?
A. There are several benefits of the mutualistic relationship between ants and acacia trees, but there are also some harmful effects.
B. There are studies which show that if ants are removed from the acacia, the acacia may suffer from overcrowding by other plants.
C. There are several benefits of the mutualistic relationship between ants and acacia trees, both providing vital services to the other.
D. There are several hundred species of ants and acacias, but the ones with mutualistic relationships are found only in tropical areas.