A user is unable to log on to a Linux workstation. The systems administrator executes the following command:

cat /etc/shadow | grep user1

The command results in the following output:

user1 :! $6$QERgAsdvojadv4asdvaarC/9dj34GdafGVaregmkdsfa:18875:0:99999:7 :::

Which of the following should the systems administrator execute to fix the issue?