To answer this question, we need to understand how the Informatica Repository server is identified.
Option A) Repository server name and port number - This option is incorrect because the Repository server is not solely identified by its name and port number. These are just components of its identification.
Option B) Repository server name - This option is incorrect because the Repository server is not solely identified by its name. It requires additional information for identification.
Option C) Repository server name and host name - This option is incorrect because the Repository server is not solely identified by its name and host name. Again, additional information is needed for identification.
Option D) Host name and port number - This option is correct because the Informatica Repository server is identified by its host name and port number. These two pieces of information together uniquely identify the server.
Therefore, the correct answer is D) Host name and port number.