ip address 192.168.0.0 255.255.254.0. Eight floors with roughly 30 to 40 users each require an address block large enough for about 320 hosts, plus growth and reserved addresses. A /23 provides 512 total IPv4 addresses and 510 usable host addresses, which is far more efficient than a /16 while still large enough for the building. A /25 supports only 126 usable hosts, and a /27 supports only 30 usable hosts, which is too small for a floor with up to 40 users if each floor needs its own subnet. Cisco CCNA 200-301 v1.1 Network Fundamentals requires subnet sizing by usable host count, not by guessing at classful ranges. The subnet mask
255.255.254.0 corresponds to /23. It fits the stated requirement with reasonable efficiency and avoids the massive waste of 255.255.0.0. Therefore, the correct router SVI addressing choice is the /23 option.