To enable Rapid Spanning Tree Protocol (RSTP), which is defined by the 802.1w standard, you should use the command that specifically sets the spanning tree mode to "rapid-pvst." This command allows the switch to use Rapid Per VLAN Spanning Tree Protocol, which is an implementation of RSTP per VLAN.
The correct command is:
Switch(config)#spanning-tree mode rapid-pvst
So, the correct answer is:
- Switch(config)#spanning-tree mode rapid-pvst