Final answer:
Registration with CLPNA is mandatory for LPNs primarily when they meet the registration requirements and intend to provide professional services, which is essential for practicing as an LPN.
Step-by-step explanation:
Registration with the CLPNA (College of Licensed Practical Nurses of Alberta) is mandatory under certain conditions for educationally-qualified Licensed Practical Nurses (LPNs). The criterion that necessitates mandatory registration is: c) Meets registration requirements. This includes when an LPN intends to provide professional services, which often involves activities such as assessing, diagnosing, and treating patients. While the act of teaching practices of a regulated profession, such as supervising regulated members, is closely related to the profession of nursing, registration may be guided by different rules and usually depends on whether the LPN is practicing or purely teaching.