Explanation/Reference:
Explanation:
D: Create a UserStore class that provides the methods for all data operations on the user. This class is equivalent to the UserStore class. In your UserStore class, implement IUserStore<TUser> and the optional interfaces required. You select which optional interfaces to implement based on the functionality provided in your app.
Interfaces to implement when customizing user store
IuserStore

The IUserStore<TUser> interface is the only interface you must implement in the user store. It defines methods for creating, updating, deleting, and retrieving users.
IuserLoginStore

The IUserLoginStore<TUser, TKey> defines the methods you must implement in your user store to enable external authentication providers. It contains methods for adding, removing and retrieving user logins, and a method for retrieving a user based on the login information.
References: https://docs.microsoft.com/en-us/aspnet/core/security/authentication/identity-custom- storageQQ-providers?view=aspnetcore-2.1