What does specifying the mapping /dev/sdc=none when lau…

What does specifying the mapping /dev/sdc=none when launching an instance do?

A.
Prevents /dev/sdc from creating the instance.

B.
Prevents /dev/sdc from deleting the instance.

C.
Set the value of /dev/sdc to ‘zero’.

D.
Prevents /dev/sdc from attaching to the instance.