You are an enterprise application developer. You are creating an application that will be used by patients to schedule appointments with a doctor. The functional specification of the application includes the following use case: 1. The user interface (UI) collects the following information from
the user: A requested date range and a requested doctor.A choice to schedule with priority given to a requested doctor or to schedule the first available appointment. 2. The UI validates the information and calls the scheduling service.3. The service queries within the date range for the requested doctor if the user chooses to schedule with priority given to the requested doctor. If no appointments are available, execute the query given in step 4.4. The service schedules with the date range if the user chooses to schedule the first available appointment. 5. The service returns a list of available appointments. The UI presents an error and returns to step 1 if no appointment is found. A team member proposes a design as shown in the exhibit. (Click the Exhibit button.) You need to make the necessary corrections to the design to ensure that the use case is correctly implemented. What should you do?

A.
Modify the diagram to perform steps 3 and 4, and then aggregate the results for all the requests.

B.
Modify the diagram to issue the request given in step 4 if the request described in step 3 returns no appointments.

C.
Modify the diagram to issue the request given in step 3 if the request described in step 4 returns no appointments.

D.
Modify the diagram to present the error described in step 3, and then issue the request given in step 5 if the request described in step 4 returns no appointments.