Cattle egrets forage (feed) in fields among cattle. The egret gets easy access to flying insects stirred up by the cattle, and the cattle don't care if they are there or not.
A. Mutualism
B. Commensalism
C. Parasitism

Nimbostratus is the correct answer.
explanation: nimbostratus clouds are the type of clouds that are mostly likely present on gray, rainy day. these clouds produce continuous rain, snow and there is no thundering or lightening either.