Creating a multiple-choice question from the given context and a 'group' which indicate the focus of the question. The question must come first, separated by <sep> from the candidate answers. The answer to the question does not have to exist in the context.

context: A person is trying to bounce a rubber ball. They drop a first ball onto rubber, a second ball onto brick, a third ball onto snow, and a fourth ball onto concrete.<sep>group: bouncing
question: Which ball bounces the least?<sep>A: rubber<sep>B: brick<sep>C: snow<sep>D: concrete