The correct option is C Commensalism
Commensalism is the interaction in which one species benefits and the other is neither harmed nor benefited.
The cattle egret and grazing cattle in close association is a classic example of commensalism. The egrets always forage close to where the cattle are grazing because the cattle, as they move, stir up and flush out insects from the vegetation that otherwise might be difficult for the egrets to find and catch.