Final answer:
The fastest delivery service offered by the United States Postal Service for a 2-pound package is Priority Mail Express, with guaranteed 1-2 day delivery.
Step-by-step explanation:
The fastest delivery service offered by the United States Postal Service for a package weighing 2 pounds is Priority Mail Express. Priority Mail Express provides overnight service to most U.S. locations, with guaranteed 1-2 day delivery. It also includes tracking and insurance up to $100.
First-Class Mail is typically used for smaller packages and has a delivery time of 1-3 days. Parcel Select Ground is a slower option that is generally used for large and heavy packages, with delivery times varying based on distance. Media Mail is a cost-effective option for shipping educational materials like books, but it has a longer delivery time of 2-10 days.