I have a question about Microsoft Certifications. What is the best Stack Exchange site to ask that question on?
The question was about MCTS, whether it is an accumulation of tests (like MCSD) or if each test is stand alone.
Questions about Certifications are usually off-topic. Asking about how the exams are like, how useful it is, etc. are all considered primarily opinion based or too broad. Asking where to get those, or where to follow courses can be seen as recommendations... off-topic too.
If you have a question about a specific question from an exam or certification, it might be on-topic on Stack Overflow if it is programming-related.
Your specific question doesn't fit in any site at the moment. Try to contact Microsoft or a partner and see if they can help.
There's not really a good site for this.
You should probably ask on Microsoft's site.