What is the purpose of the Durable Functions entity (Entity Functions)?

1. A Replaces orchestrator functions
2. ✓ B Implements stateful, actor-like objects that handle operations and maintain state durably (correct answer)
3. C Provides fan-out to multiple activities
4. D Acts as a service bus consumer

Shortcut: Entity functions (virtual actors) maintain durable state and handle operations (methods) sent to them. State is persisted between invocations without managing storage explicitly.