How can a Salesforce admin enable this capability in the Community using configuration?

Universal Containers plans to use person accounts for the external consultants. They need to allow their consultants to register using the Community.

How can a Salesforce admin enable this capability in the Community using configuration? Select one or more of the following:
A . Allowing users to self register and create a workflow to update contacts to Person Account
B . Add a Person Account option to the user registration page and have the option selected by default
C . Provide a link to a custom web page that allows external consultants to register and use Salesforce API to create Person Accounts
D . Enable Allow External Users to self-register in a Community Management and leave the account field blank

Answer: D