Which of the following is the purpose of a private VLAN (PVLAN) in Cisco?

Which of the following is the purpose of a private VLAN (PVLAN) in Cisco?

• A secured VLAN with no outside access.
• A VLAN with only one port or interface assigned to it.
• A VLAN that is only configured on a single switch.
• Allows access to a resource (like the internet), but not between access ports. 

EXPLANATION

A private VLAN would be used in an application like a motel. There would be certain port(s) that would allow access to the internet, DNS servers, etc. But the access ports that may connect to each motel room would be isolated from each other. This means that room one can't see room two or the other way around, but they can both get to some servers or the internet.
You could have a VLAN on only one switch, but this is not a private VLAN.

A VLAN with only one port or interface is also not a private VLAN and having only one member would mean it is basically useless.
While private VLANS improve security it is not generally the same as having a VLAN that can't connect outside of the VLAN.