Which speicalty I should choose (BD+C or ID + C)?

Hi Tristan, I am a lighting designer that responsible both for the exterior and interior lighting of different kind of project such as government urban area or luxury retails, I have just passed the Green Association Exam, i want to go on to get the AP, but which specialty i should choose? BD+C or ID + C? It seems some content of BD cover the ID, so is better to choose BD+C, right? And pls help to tell me your corresponding charge including the online project experience assignment for both of them. Thanks and Best Regards, Eric