What is the potential impact to the architecture if NTO decides to implement this feature?

Northern Trail Outfitters (NTO) uses the Customer 360 Platform implemented on Salesforce Experience Cloud. The development team in charge has learned of a contactless user feature, which can reduce the overhead of managing customers and partners by creating users without contact information.

What is the potential impact to the architecture if NTO decides to implement this feature?
A . Custom registration handler is needed to correctly assign External Identity or Community license for the newly registered contactless user.
B. If contactless user is upgraded to Community license, the contact record is automatically created and linked to the user record, but not associated with an Account.
C. Contactless user feature is available only with the External Identity license, which can restrict the Experience Cloud functionality available to the user.
D. Passwordless authentication can not be supported because the mobile phone receiving one-time password (OTP) needs to match the number on the contact record.

Answer: C