Folk dance strengthens an individual's bond to a community

Halfway through this composition two of the voices engage in?

a) drop out b) repeat but in rhythmic augmentation c) retrograde repetition of the work's opening half d) repeat but omit their texts

Suppose that under its collective bargaining agreement the ABC Corporation can hire nonunion workers, but such workers must join the union within 30 days. This agreement embodies:

A. an open shop. B. a closed shop. C. a union shop. D. an agency shop.