which additional command keyword should be added if you would like to use these keys on another router or have the ability to back them up to another device?

Given the Cisco IOS command crypto key generate rsa label MY_KEYS modulus 2048, which
additional command keyword should be added if you would like to use these keys on another
router or have the ability to back them up to another device?

A.
redundancy

B.
exportable

C.
on:USB smart-token

D.
usage-keys