What would be required to enable sending emails from their new domain without impacting deliverability?

Northern Trail Outfitters (NTO) uses the SAP domain comms.nto.com and has just opened an office in Australia. They have created a business unit for their new office and want to use the domain comms.nto.com.au to send emails to their Australian customers.

What would be required to enable sending emails from their new domain without impacting deliverability?
A . An additional IP address
B. An additional Sender Authentication Package
C. An additional private domain
D. Register the new domain in Setup > From Address Management

Answer: B

Explanation:

A Sender Authentication Package (SAP) is a set of features that authenticate an email sender’s identity and reputation, such as a private domain, a dedicated IP address, a link customization, and a reply mail management. By having an additional SAP for the new domain comms.nto.com.au, NTO can send emails from their new domain without impacting deliverability. An additional IP address is not required if they already have one for their SAP. An additional private domain is not enough to authenticate their sender identity and reputation. Registering the new domain in From Address Management is not necessary if they have an SAP for the new domain.

References:

https://help.salesforce.com/articleView?id=sf.mc_es_sender_authentication_package.htm&type=5

https://help.salesforce.com/articleView?id=sf.mc_es_from_address_management.htm&type=5