To raise an arm upward, the muscle on one side of its contracts. What happens to the muscle on the opposite side of the arm? A. contracts B. relaxes C. both contracts and relaxes D. neither contracts nor relaxes

B. it relaxes

Explanation:

Antagonisms. one muscle contract while the opposite one relaxes to carry out an action.

that would be called plucking : )

explanation:

''plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the erosion and transportation of individual pieces of bedrock, especially large "joint blocks". as a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock."