Which of the following would convey a positive attitude?

A smile is universally recognized as a gesture that conveys warmth, friendliness, and approachability. It creates a positive atmosphere and fosters effective communication, both of which are essential in a medical administrative environment where interacting with patients and colleagues is part of the daily routine. A genuine smile can make others feel more comfortable, enhance trust, and promote a sense of well-being. It serves to create a welcoming environment which is crucial in healthcare settings, where patient comfort and satisfaction are priorities.

Other options such as a fist, frown, or clenched teeth typically convey frustration, anger, or discomfort, which do not promote a positive interaction. Thus, the choice of a smile stands out clearly as the most effective means of conveying a positive attitude.