Final answer:
Sal and Chris are in the avoiding stage of Knapp's model of relationship development, where they actively avoid interaction with each other.
Step-by-step explanation:
Sal and Chris are in the avoiding stage of their relationship based on Knapp's model. This is the ninth stage where individuals take steps to minimize or eliminate interaction with one another, indicating significant deterioration in the relationship. They may exhibit behaviors such as staying out of each other's way, which aligns with the scenario presented where Sal and Chris ensure they do not have to be in one another's presence, finding it unpleasant even to share the same room.