Refer to the exhibit. PCs in VLAN 2 are not able to communicate with PCs in VLAN 3.  What could  be the cause？（）

• A、 IP routing is not enabled.
• B、 VTP is not configured correctly on the interfaces.
• C、 The command mls rp management-interface is missing.
• D、 The command mls rp ip must be disabled to enable the routing.