To enable asynchronous invocation on a method that returns a value, two things must be done:
1. The method's return type must be return Future<V> in the bean class as well as in the interface.
Quote from specs: 4.5.2.2
Alternatively, the bean-class method of an asynchronous method that is exposed via a Local or Remote business interface can be written without explicit use of the Future<V> API. In this case, the bean-class method declares a return type of V, where the same type appears as the parameterized type of Future<V> in the corresponding business interface method signature.
2. Put @Asynchronous annotation on the method definition in the bean class code. There is no need to apply this annotation in the method declaration in the remote interface.
Quote from specs: 4.5.1
@Asynchronous can be applied to a business method of a bean class or to a method of a Local/Remote business interface.
Line 10 should be a correct answer too