Refer to the exhibit. An architect must design an IP addressing scheme for a multisite network connected via a WAN transit. The campus site must accommodate 12,000 devices and the branch sites must…

A /18 network provides 2^(32-18) - 2 = 2^14 - 2 = 16,382 usable IP addresses. This comfortably accommodates the 12,000 required devices for the campus site, leaving sufficient room for future growth while conserving address space more efficiently than larger blocks.

A /16 network provides 2^16 - 2 = 65,534 usable addresses, which is significantly more than 12,000 devices, leading to inefficient use of address space and larger routing tables.

A /10 network provides 2^22 - 2 = 4,194,302 usable addresses, which is an extremely large block and highly inefficient for 12,000 devices, wasting vast amounts of address space.

A /20 network provides 2^12 - 2 = 4,094 usable addresses. This is insufficient to accommodate 12,000 devices for the campus site.