I just re-read the OP's post and noticed they think they are coming into Concourse D. The "Terminal A" in the title is my fault, as I misread the post when I added detail that was missing.

If we are talking about a D --> C transfer, than it's just a walk down one long concourse.

However, more UX flights go into A than D, so the above information is helpful.

Sorry again for the confusion.