Which delivery method does not guarantee that the packet will be delivered fully without errors?

The delivery method that does not guarantee that the packet will be delivered fully without errors is known as "Best Effort Delivery." This method is commonly used in connectionless protocols such as the User Datagram Protocol (UDP).

In Best Effort Delivery systems, the network makes no guarantees that packets will arrive at their destination. This means that packets may be lost, duplicated, or arrive in a different order than they were sent. Because of this, it is the responsibility of the application-layer protocols to handle errors and ensure data integrity if needed.

In contrast, protocols such as Transmission Control Protocol (TCP) provide guaranteed delivery through methods such as acknowledgments, retransmissions, and error-checking mechanisms. Therefore, if reliable delivery is a requirement, TCP is preferred over UDP and Best Effort Delivery methods.