Which two statements are true regarding the Automatic Storage Management (ASM) instance created on a Linux machine?

Which two statements are true regarding the Automatic Storage Management (ASM) instance created on a Linux machine? (Choose two.)

A.
You can allocate only a whole disk for ASM.

B.
You can perform an RMAN backup of the ASM disks.

C.
You cannot change the redundancy of the diskgroups.

D.
You can have only one ASM instance on one Linux machine.