Translation:the Klingon consonant D
The placement of the tongue for the Klingon r is very close to the English "d" like, so I'm not surprised that it is a little difficult to distinguish those sounds.
Unfortunately Duolingo assumes that single letter errors are typos, so it becomes near impossible to be strict on individual words that are only one letter apart.
Thanks for the quick response. Later in the lesson, there was another instance where it showed the word 'Day' as it was being pronounced, and it definitely sounded the same as the first time. I think if I had gotten this question first, I would have been fine. I'm using the speakers on my smartphone for the audio portion, and this pronunciation comes across as a really soft "d". It actually sounds more like a "th" as in "they" or "that", while the "r" in 'ray' has more of a tongue roll that I thought I was hearing but wasn't. I'll have to try and keep some headphones handy from now on to see if that makes it better. Thanks for the help!