Mount Point Mystery

A 10MB disk image file at /opt/disk.img contains an ext4 filesystem with an important file inside. Your job is to mount this disk image to /mnt/data and verify you can access the file called "secret.txt" inside it. The mount point /mnt/data already exists but is empty. The disk image needs to be mounted there using the loop device. Note: Since you cannot use sudo, the setup has already configured the mount permissions. Use the provided helper script at /usr/local/bin/do_mount.sh to mount the image (it has the appropriate SUID bit set).