While this question gives your interviewer insight into the diversity of your programming language experience, they most importantly want to know that you are adaptable and able to learn on the fly if needed. Talk about the different languages that you consider yourself fluent in and, if possible, do as much research into Redseal Systems as you can prior to your interview and try to speak to the specific languages that they work with.
"During my training to be an engineer and then in my current role since graduating, a majority of my experience falls within Python. My current role delves deeply into artificial intelligence and Python is awesome with this advanced technology. As I understand it from talking to another engineer here at Redseal Systems, a requirement would be for me to learn Scala. Though I haven't worked directly with Scala, I believe my experience and willingness to learn would have me up and running in no time if hired for this role."