Which of the following can constitute grounds for denial of a license?

The basis for denying a license to practice as a Physical Therapist Assistant in Florida is particularly grounded in concerns for safety and ethical standards. The correct answer highlights the critical issue of being unable to practice safely due to the influence of drugs or alcohol. In the healthcare field, maintaining the ability to perform one's duties without impairment is paramount. Practicing under the influence compromises not only the quality of care provided to patients but also raises significant legal and professional liability issues. Regulatory boards prioritize patient safety, and any indication of impairment due to substance use is taken very seriously, often resulting in a denial of licensure.

The other options, while concerning in varying degrees, do not directly represent grounds for denial. For instance, practicing without a supervisor may violate specific regulations, but this alone may not automatically result in a denial. Similarly, working outside of Florida does not inherently disqualify an applicant, as licensing laws pertain specifically to the jurisdiction in which the practice is intended. Having a large number of patients may suggest a busy practice but does not directly correlate with incompetence or impairment. Thus, the focus on the safe practice aspect with respect to drugs or alcohol underlines the importance of professionalism and public safety in the standards for obtaining a license.