What configuration change should be made to Office1 to resolve its connectivity issues?

Enabling DHCP (Dynamic Host Configuration Protocol) is the correct action to take for resolving connectivity issues in this context. DHCP automates the process of assigning IP addresses to devices on a network. When DHCP is enabled, Office1 will be able to obtain an appropriate IP address, subnet mask, default gateway, and DNS server information automatically from the DHCP server. This is essential for ensuring that the device can communicate effectively with other devices on the network and access external resources.

In many scenarios where connectivity problems occur, it may be due to misconfigured or missing network settings. By enabling DHCP, you ensure that the system receives the correct settings dynamically, reducing the risk of human error associated with manual configurations.

Setting a static IP address might solve connectivity issues if the network requires a specific IP, but it may also cause conflicts with other devices if not managed correctly. Changing the Ethernet card could potentially resolve hardware-related issues, but is not usually the first step to troubleshoot connectivity problems. Updating only the subnet mask may not address the root cause of the connectivity issue if other settings are also misconfigured; therefore, enabling DHCP is a more comprehensive solution that addresses potential problems in multiple areas of network configuration.