Final answer:
The error indicates that CI identification failed because port 1433 is closed on the host, preventing Service Mapping from correctly mapping services.
Step-by-step explanation:
The correct statement that describes the reason for the error message "Service Mapping Error: Failed to identify CI on host myhostname. The application port 1433 is closed." is that b) The CI identification failed due to a closed port (1433) on the host myhostname. Port 1433 is commonly used by Microsoft SQL Server, which is why a failure to identify a Configuration Item (CI) can often be attributed to the application port being inaccessible or closed. Service Mapping is a process used to discover and map the relationships between IT components in an ITSM (IT Service Management) context, therefore a closed port would prevent it from correctly identifying and mapping services running on a host.