A valid IPv6 address is formatted as eight groups of four hexadecimal digits, separated by colons. The option 2001:0db8:3000:2215:0000:0000:aaaa:1111 fits this format, making it the correct choice.

The correct simplified IPv6 address for 2001:0000:1000:0000:0000:cbff:0020:0001/64 is 2001:0:1000::cbff:20:1/64. In IPv6, leading zeros within each segment can be removed, and consecutive segments of zeros can be replaced by a double colon (::). As such, 2001:0000:1000:0000:0000:cbff:0020:0001 simplifies to 2001:0:1000::cbff:20:1.

UDP (User Datagram Protocol) is faster than TCP because it has less overhead since it does not require establishing a connection before data is sent. UDP operates at the Transport Layer, which is responsible for end-to-end communication. Additionally, UDP data is sent on a best-effort basis, meaning it does not guarantee delivery, ordering, or error checking, which further contributes to its speed but lower reliability.