What additional step must be taken if users receive a ‘connection refused’ error when attempting to access the router via SSH?

A router is being enabled for SSH command line access.
The following steps have been taken:
• The vty ports have been configured with transport input SSH and login local.
• Local user accounts have been created.
• The enable password has been configured.
What additional step must be taken if users receive a ‘connection refused’ error when attempting to
access the router via SSH?

A.
A RSA keypair must be generated on the router

B.
An access list permitting SSH inbound must be configured and applied to the vty ports

C.
An access list permitting SSH outbound must be configured and applied to the vty ports

D.
SSH v2.0 must be enabled on the router