Final answer:
The Delta service that provides priority check-in, exclusive reservation line, and priority boarding is called Delta Sky Priority.
Step-by-step explanation:
The Delta service that allows passengers priority check-in, exclusive reservation line, and priority boarding is called Delta Sky Priority. This service is available for Delta One, Delta Premium Select, First Class, and Delta Comfort+ passengers. With Delta Sky Priority, passengers receive expedited services such as dedicated check-in counters, faster security screening, priority boarding, and baggage handling.