As an IT professional, you have been asked to improve security for employees using company$-$issued laptop computers. To do so$,$ you implement Defense$-$in$-$Depth $($DiD$).$ Which of the following activities best describes your actions to achieve this objective?

$1$ point

The use of encryption to protect data integrity and confidentiality

The process of regularly updating software to address vulnerabilities

Requiring validation of user input before it is copied to buffers

The implementation of multiple layers of security measures