Which statement is correct about the EntityManager API?

• A. The merge, persist, remove, and getReference methods must be invoked within a transaction context.
• B. It is safe (no exception is thrown) to call merge or getTransaction on a JTA EntityManager instance.
• C. The getReference method can throw an EntityNotFoundException.
• D. Runtime exceptions thrown by the refresh and createQuery methods of the EntityManager interface do NOT cause the transaction to be rolled back.