Final answer:
The criteria least likely used when selecting a physician for medical referral is the location of the physician's office.
Step-by-step explanation:
The least likely criterion used when selecting a physician for medical referral would be the location of the physician's office. While patient feedback, trust of a physician, and recommendation of a colleague are all important factors in selecting a physician, the location of the physician's office is not usually a primary consideration. Patients are more likely to prioritize factors such as the reputation of the physician, the physician's expertise in the specific medical condition, and the convenience of the office hours.