Final answer:
Looking at a watch while the patient answers a question does not promote effective therapeutic communication as it suggests impatience and a lack of engagement.
Step-by-step explanation:
The action that does NOT promote effective therapeutic communication when performed by a medical assistant is c. looking at a watch while the patient answers a question. Effective therapeutic communication requires active listening and exhibiting behaviors that show the patient they are being heard and respected. Making direct eye contact, taking notes, rephrasing to clarify understanding, and nodding in agreement are all actions that contribute to a positive communication environment. In contrast, looking at a watch may signal to the patient that the medical assistant is not fully engaged or is impatient, thereby disrupting the rapport and trust between the patient and the healthcare provider.