Final answer:
b. HEDIS. HEDIS is the data set that helps healthcare consumers identify the best-performing health plan.
Step-by-step explanation:
The data set that helps healthcare consumers identify the best-performing health plan is HEDIS (Healthcare Effectiveness Data and Information Set). HEDIS is a tool used to measure performance in areas such as preventive care, chronic disease management, and member satisfaction. It provides standardized and comparable information to help consumers make informed decisions about their health plan choices.