Hi!! can somebody help me with this question? which is the best example of commensalism?

A. honey bees feed on the pollen of cornflowers and help the flowers reproduce

B. barnacles ride on a gray whales back to obtain food, and the whale is not harmed

C. squirrels and chipmunks eat the same nuts in a forest where food is scarce

D. prairie dogs often collect and eat food in groups so they are better protected from enemies

thx to anybody that helps! ♡︎