Users in the office report that the speed of the Internet has drastically decreased since the recent network hardware refresh. Which of the following could be attributed to the problem?

If the firewall were not powered on, internet access would be completely blocked for all users, not merely slowed.

A malfunctioning DHCP server would cause IP assignment failures and loss of connectivity, not a general speed degradation.

A cellular repeater could introduce wireless interference but would not affect the speed of wired switch connections or cause a drastic uniform slowdown.

If the replacement switches have their ports hard-set or auto-negotiated down to 10 Mbps, every device connected to those switches is limited to 10 Mbps, causing a dramatic reduction in perceived internet speed across the office. This is a common misconfiguration after hardware swaps when duplex and speed settings are not verified.