Your web application uses a session bean component in a distributed application to make a specialized calculation such as validating credit card numbers. However, you want to shield your web component from the code involved with looking up session bean component and using its interface.
You want to decouple the local application classes from the looking up and use a distributed component whose interface could change. Which
J2ee pattern is appropriate?
A. Transfer Object
B. Service Locator
C. MVC
D. Business Delegate
Answer in HFSJ states only "D". Why cannot it also be B? I mean should BOTH B and D be the answers?