Refer to the Exhibit.
— Exhibit –=================== Bootstrap installer starting ===================
Initialized the environment
Routing engine model is RE-S-1800×4
Discovered that flash disk = ad0 , hard disk = ad1
mount: /dev/ad1s1f : Invalid argument
ERROR: mount_partition: Mount /dev/ad1s1a /mnt failed
You are now in a debugging subshell (you may not see a prompt)…
#
— Exhibit –During the boot of your MX480, you see the output shown in the exhibit.
Which three statements are true? (Choose three.)

A.
The Routing Engine cannot mount the partition to complete booting.

B.
Running fsck on the partition might resolve the boot problem.

C.
You must swap the Routing Engine over to the backup slot to get it to boot properly.

D.
The boot failed because one of the file systems is in an inconsistent state.

E.
The boot failed because a USB drive has been inserted into the device.

Explanation: