What are the possible alternatives for partially performed operation by a legacy application? Expose legacy application as a service Implement medi...

What are the possible alternatives for partially performed operation by a legacy application?
Expose legacy application as a service
Implement mediation
Implement service component
Change legacy application
The implementation of a new service component is usually chosen when the legacy application is planned for discontinuation or replacement.
In the case of a logic gap, mediation could implement the logical steps not performed by the existing operation, or invoke another operation that implements the missing steps.
In the case of a data gap, mediation could generate the missing information or retrieve it from another source, such as another service operation or a database (legacy application).
The creation of new operations or services to encapsulate access to the legacy system is one of the possible solutions for partially performed operations by a legacy application.
a) 1, 2, 3, 4
b) 1, 2, 4, 3
c) 2, 1, 3, 4
d) 3, 2, 1, 4