Final answer:
Carla is displaying the defense mechanism of Projection.
Step-by-step explanation:
The defense mechanism that Carla is displaying here is Projection.
In projection, a person refuses to acknowledge their own unconscious feelings and instead sees those feelings in someone else. In this case, Carla is worried that she talks too much, but instead of acknowledging her own behavior, she accuses her roommate of talking too much and not listening.
For example, Carla may be avoiding accepting her own tendencies to dominate conversations and project her insecurities onto her roommate.