How could these auto-reply messages be enabled?

Northern Trail Outfitters (NTO) send emails from Content Builder and Journey Builder. When subscribers reply to an email, NTO would like to send an auto-reply message using a pre-defined HTML email that explains email replies are unmonitored and they should call NTO for any inquiries.

How could these auto-reply messages be enabled?
A . From the Reply Mail Management settings page, choose the ‘Create Custom Response’ option under ‘Automated Response Email for Remaining Replies’ section and select the HTML email from the ‘define email’ link.
B . Create a Triggered Send and on the Reply Mail Management settings page, choose the ‘Create Custom Response’ option under ‘Automated Response Email for Remaining Replies’ section, then select the Triggered Send email.
C . Create a Triggered Send and from a Sender Profile properties page, enable ‘Custom Reply Mail Management Settings’, ‘Use Auto Reply’ and ‘Reply using triggered send’ options, then select the Triggered Send email.
D . Open Admin > Account Setting page in Email Studio and in the ‘Auto Reply Email’ section, select ‘Custom’ and paste the HTML email code into the text area field.

Answer: A