Which approach allows for more complex validation scenarios beyond what Data Annotations can provide in Entity Framework?

The Fluent API in Entity Framework allows for more complex validation scenarios beyond what Data Annotations can provide. While Data Annotations offer a convenient way to define basic validation rules directly within entity classes, the Fluent API provides more flexibility and control over the validation process. Developers can use the Fluent API to create custom validation logic, perform conditional validation, and handle complex validation scenarios that cannot be expressed with Data Annotations alone.