Which action would reduce future maintenance costs?

You are the architect of an existing project. Making changes to one component frequently requires
making changes to many other components.
Which action would reduce future maintenance costs?

A.
Redesign the configuration and deployment.

B.
Add an abstraction layer between the servlets and the EJB components.

C.
Convert all stateful EJB components to stateless EJB components.

D.
Expose the existing EJB components as web services.