An Administrator Thinks the UNIX Systems May Be Compromised, but a Review

An administrator thinks the UNIX systems may be compromised, but a review of system log files provides no useful information. After discussing the situation with the security team, the administrator suspects that the attacker may be altering the log files and removing evidence of intrusion activity. Which of the following actions will help detect attacker attempts to further alter log files?

A) Enable verbose system logging
B) Change the permissions on the user's home directory
C) Implement remote syslog
D) Set the bash_history log file to "read only"