How does Magento store customer address attribute values?

A. Customer address is a flat entity, so all values are stored in the customer_address_entity table
B. Customer address is not an entity, so its properties are customer attributes
C. Customer address is an attribute of the customer, so it doesn’t have its own attributes
D. Customer address is an EAV entity, so all values are stored in the customer_address_entity table and related values tables