Some users are unable to access their workstations.

The workstation's IP configuration (192.168.1.27/24 with gateway 192.168.1.1) shows that it has a correct IP address, correct subnet mask, and expected default gateway for a typical small office network. Because the IP is in the correct private range and not an APIPA address (169.254.x.x), this also confirms that DHCP is functioning properly. Therefore, option D (DHCP) cannot be the cause.

The user then pings the default gateway at 192.168.1.1, which should be the router—the device providing routing between local devices and outside networks. The repeated "Request timed out" responses indicate the workstation cannot reach the router at all. This type of failure points directly to a router outage, a powered-off router, a failed router interface, or a physical disconnection of the router from the switch.

If DNS (C) were the issue, the user would still be able to ping the IP address of the gateway because DNS is not required for IP-to-IP connectivity. A web server (A) has no relation to local gateway communication and does not affect workstation access.

Since the workstation has a valid IP but cannot reach its default gateway, the failure point is the router.