Which set of commands is recommended to prevent the use of a hub in the access layer?

Switch(config-if)#switchport mode access switch(config-if)#switchport port-security maximum 1

Port security is only used on access port (which connects to hosts) so we need to set that port to access mode, then we need to specify the maximum number of hosts which are allowed to connect to this port -> C is correct. Note: If we want to allow a fixed MAC address to connect, use the switchport port-security mac-address command.