The following statements are true for the Financial Services Cloud Person Account Data Model:
The Person Account is a virtual object displaying data from Accounts and Contacts objects. It represents all aspects of the person and includes data such as date of birth or tax ID number. You can use Person Accounts to store information about individual people by combining certain Account and Contact fields into a single record.
The Person Account model uses the standard Account object to hold all of the details about a person. The Account object has been extended with custom fields and a Person Account Record Type. You can use Person Accounts to simplify your data model and reduce the number of records you need to manage.

To create a new Business Milestone Type, you need to add a new picklist value on the Milestone Type field of the Business Milestone object. This field is used to categorize the different types of business milestones that can be tracked for a client. Verified Reference: : Salesforce Financial Services Cloud Implementation Guide, page 57.

Explanation
The following referral metrics are tracked with custom components included in Financial Services Cloud:
Expressed interests: This metric shows the number of referrals that have a specific expressed interest, such as a mortgage, a credit card, or a checking account. You can use this metric to understand the customer needs and interests that generate the most referrals.
My Top Referrers: This metric shows the top referrers who have created referrals for you, ranked by the number of referrals and the conversion rate. You can use this metric to identify and appreciate your best sources of business.
Referrals Assigned to me: This metric shows the number of referrals that are assigned to you and their status, such as New, In Progress, or Closed. You can use this metric to monitor and manage your referral pipeline and prioritize your follow-up actions. Verified References: : Salesforce Financial Services Cloud User Guide, page 40. : Salesforce Financial Services Cloud User Guide, page 41. : Salesforce Financial Services Cloud User Guide, page 42.