Which of the following tasks should the nurse delegate to an assistive personnel?

The correct answer is B because using a pain rating scale to monitor a client's pain level is a task that can be safely delegated to an assistive personnel. This task involves objective measurement and does not require specialized nursing knowledge or judgment. Assistive personnel can be trained to accurately use pain scales and report findings to the nurse for further assessment or intervention. Suctioning a tracheostomy, performing a dressing change on a central catheter, and instructing a client on enema administration require specific nursing skills, assessment, and critical thinking, making them inappropriate for delegation to assistive personnel.