正解:A
The verified answer is A. DHCP can provide the default gateway to Windows workstations as part of the leased IP configuration. The router option tells the client which gateway to use for off-subnet destinations.
Cisco CCNA 200-301 v1.1 places this skill in IP Services, where the exam expects a working understanding of how the feature behaves on real Cisco networks, not just a memorized command. STP prevents switching loops, SNMP monitors devices, and DNS resolves names; none of those supplies the default gateway address to the host. In production, this distinction matters because a misapplied command or design choice usually creates an outage, a security gap, or unnecessary troubleshooting noise. The correct choice matches the control-plane, data-plane, wireless, security, or services behaviour described in the scenario and should be preferred over options that merely sound related.