A computer must be added to an IPv6 subnet by your network administrator. Which of these IPv6 addresses is on the same subnet as 2601:0:0:0f:1a:308c:2acb:fee2?

The address in the question and the option 2601::0f:ab:cd:123:4a both have a subnet of 0f. IPv6 addresses are 128 bits long and are broken into 8 hextets by colons (:). As a result, each hextet represents 16 bits. Leading 0s can be removed, as can consecutive groups of 0s at one place in each address, represented by double colons (::). The Interface ID is the last 64 bits (4 hextets) of an IPv6 address that identifies the specific computer. The first 64 bits are referred to as the prefix. /48 prefixes are assigned to ISPs and very large organizations. Subnets are defined by the next 16 bits (the fourth hextet). The fourth hextet of option 2601::of:308c:47:4321 is 0. Option fe80:ab:bc:0f:1a:308c:2abc:fee5 is a link-local address. Option 2601:0:0:0x::2acb:ac01 is an invalid number because hex numbers only go to letter f.