Final answer:
The nursing manager should consider assigning sterile or invasive procedures to professional nurses with the appropriate expertise.
Step-by-step explanation:
When assigning procedures to professional nurses in a hospital unit, the nursing manager should consider the principle of assigning sterile or invasive procedures to professional nurses with the appropriate expertise (Option C). This ensures that patients receive the specialized care they require, leading to optimal outcomes. Professional nurses have the necessary knowledge and skills to perform these complex tasks safely and effectively. By assigning these procedures to experienced nurses, the nursing manager also promotes staff development by allowing newer nursing staff to observe and learn from their more experienced colleagues.