IANA

BCD.

The Internet Assigned Numbers Authority (IANA) is a department responsible for managing global IP address allocation, managing the root zone in the Domain Name System (DNS), and defining URI schemes for use on the Internet. The following are the three true statements about IANA:

B. IANA oversees global IP address allocation: IANA manages the allocation of IP addresses, AS numbers, and other Internet protocol resources to regional Internet registries (RIRs) that manage IP address blocks for their respective regions.

C. IANA managed the root zone in the DNS: IANA manages the root zone in the DNS, which is the top-level of the DNS hierarchy. It is responsible for adding, deleting, and modifying top-level domains (TLDs) and ensuring that the DNS root zone is properly maintained.

D. IANA is administered by the ICANN: IANA is administered by the Internet Corporation for Assigned Names and Numbers (ICANN), which is a non-profit organization that is responsible for coordinating the maintenance and management of the Internet's unique identifiers, such as domain names, IP addresses, and protocol parameters.

A. IANA is a department that is operated by the IET: This statement is false. IANA is a department that is operated by ICANN, not the IET.

E. IANA defines URI schemes for use on the Internet: This statement is partially true. While IANA does maintain a registry of URI schemes, it is not solely responsible for defining them. URI schemes can be defined by various organizations, including the Internet Engineering Task Force (IETF).

In summary, the correct options are B, C, and D.