Choose the correct word. Read the article "That" and "which": Which is which? to help you out.

1. At five minutes to midnight, Raymond ended the party with an off-key rendition of “The Way We Were,” (that/which) caused the guests to flee in pure disgust.a) thatb) which
2. The sounds of the many creatures (that/which) lurked in the forest frightened us as we lay in our tent.a) thatb) which
3. The collection agency (that/which) came looking for you yesterday left two notices outside your apartment door.a) thatb) which
4. The television series M*A*S*H, (that/which) depicted life in an army hospital during the Korean War, was based on a film of the same name.a) thatb) which
5. Anita, whose bedroom was never very tidy, could no longer see the floor under the piles of dirty gym clothes, underwear and towels (that/which) had accumulated.a) thatb) which