An administrator is troubleshooting a database service outage that was reported by a monitoring system.

An administrator is troubleshooting a database service outage that was reported by a monitoring system. Given the following output:

$ systemctl status mariadb

Oct 20 16:40:45 comptia systemd[1]: mariadb.service: Main process exited, code=killed, status=9/KILL

Oct 20 16:40:45 comptia systemd[1]: mariadb.service: Failed with result 'signal'.

Oct 20 16:40:50 comptia systemd[1]: Stopped MariaDB 10.3 database server.

$ dmesg

[ 1061.491433] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom, task_memcg=/system.slice/mariadb.service, task=mysqld,pid=1981,uid=27

[ 1061.491453] Out of memory: Killed process 1981 (mysqld) total-vm:330668kB, anon-rss:31316kB, file-rss:OkB, shmem-rss:OkB, UID:27 pgtables:324kB oom_score_adj:0

Which of the following is the reason for the outage?