Santiago is a new network engineer for a mid$-$sized company. It is his responsibility to ensure that all employees working from home are able to connect to the office network in an efficient and secure manner. He must provide a service that allows communications between out$-$of$-$office staff and network resources to be encrypted at the protocol level and to be performed by either client or server software. The solution must also ensure that even if protocol encryption fails, the data is safe by its own encryption. What solution does he select?

Authentication, authorization, and accounting $($AAA$)$

Implementation of a demilitarized zone $($DMZ$)$

Identity and access management $($IAM$)$

Virtual private network $($VPN$)$