Which of the following is an authorized act for a pharmacist?

The authorized act for a pharmacist includes dispensing, selling, compounding drugs, and prescribing under regulations. This encompasses a broad range of responsibilities crucial to patient care and medication management. Pharmacists are trained professionals with significant knowledge of medications, their interactions, and proper usage. As such, they are empowered to carry out these tasks to ensure that patients receive appropriate and effective therapy tailored to their specific needs.

Under the regulations governing pharmacy practice, pharmacists are not limited to merely dispensing medications; they also play a vital role in compounding personalized medications when required and can initiate therapy through prescribing, depending on their scope of practice and provincial regulations.

Counseling patients on medication—although an essential part of a pharmacist's role—is only a fraction of what they are authorized to do. Similarly, the distribution of over-the-counter medications is part of their practice but does not fully encapsulate the breadth of their professional capabilities. Conducting laboratory tests for patients typically falls outside the scope of practices allowed for pharmacists unless there are very specific regulations enabling them to perform such tests, which isn't a standard function in most jurisdictions.

Thus, option C accurately represents the comprehensive scope of practice authorized for pharmacists, aligning with their training and the legal framework that governs pharmacy practice.