A. The Standardized Service Contract principle can be applied to ensure that the new service capability extends the existing service contract in a manner that is compliant with current design standards. The Redundant Implementation pattern can be applied to establish separate implementations of Service A that include duplicate databases with copies of the data that Service A requires from the shared database.

B. The Service Autonomy principle can be applied to further isolate the individual implementations of Service A by separating them onto different physical servers. When the new service capability is added, the Service Data Replication pattern can be applied to give each implementation of Service A its own copy of the data it requires from the shared database.

C. The Service Loose Coupling principle can be applied together with the Standardized Service Contract principle to ensure that Service Consumer A is not indirectly coupled to the shared database after the new service capability is added to the service contract. The Legacy Wrapper pattern can be applied to establish a new utility service that will provide standardized data access service capabilities for the shared database.

D. The Service Autonomy principle can be applied to further isolate the individual implementations of Service A by separating them onto different physical servers. When the new service capability is added, the State Repository pattern can be applied to give each implementation of Service A its own copy of the data it requires from the shared database.