Final answer:
The four-digit numeric code established by the National Uniform Billing Committee (NUBC) that classifies a line item in the chargemaster is the Revenue code.
Step-by-step explanation:
The four-digit numeric code established by the National Uniform Billing Committee (NUBC) that classifies a line item in the chargemaster is d) Revenue code. Revenue codes are used in healthcare billing to identify and categorize the services provided to a patient. They are used by hospitals and healthcare facilities to track and bill for services.