To support at least 260 hosts, you need at least 512 total IP addresses (accounting for network/broadcast overhead). /23 (255.255.254.0) gives 510 usable IPs, ideal for 260 devices with minimal waste. /24 (255.255.255.0) gives only 254 usable - not enough. /22 (1022 usable) and /21 (2046 usable) would work but result in significant address waste. # Reference: CompTIA Network+ N10-009 Official Objectives: 2.1 - Given a scenario, configure and apply IP addressing schemes.