$27\mathrm{.}3\%$ complete

Question

An e$-$commerce company recently identified suspicious activity on its web$-$based application, suggesting a zero$-$day exploit. The security team suspects that a vulnerability in the application might be under active exploitation by malicious actors before the company identified it$.$ With no known fixes available for a zero$-$day exploit, what should be the initial course of action for the security team to minimize potential damage and safeguard the application and its users before a patch is available?

A$.$Perform a comprehensive system backup.

B$.$Implement intrusion detection systems and application firewalls.

C$.$Update the antivirus software on all company devices.

D$.$Enforce password changes for all users.