Final answer:
The immune system's primary functions are to avoid, detect, and eliminate infections. It does not create infections; this is not a function of a healthy immune system.
Step-by-step explanation:
The answer to the question which of the following is not a primary function of a healthy immune system is: d. the immune system creates infections. A healthy immune system's primary functions include avoiding infections, detecting infections, and eliminating infections; it does not create infections. Instead, it actively works to defend the body against infections and other causes of disease such as cancerous cells. The immune system includes mechanisms such as immune surveillance that help identify and destroy harmful entities, including tumor cells. This highly complex system operates as the body's defense line against various pathogens, ensuring the maintenance of health.