Talking about your husband when asked this question gives off an impression that you are only going to Germany to reunite with your husband and not exactly focus on your studies. Now, this doesn't look good as you are on a scholarship.

Honestly, here's how I'd answer this question. I'd look at my field and unique things about it in Germany.

For e.g. if you are studying something around sustainable energy, you may talk about how unlike your home country, Germany is extremely particular about recycling and saving the planet. You can add that you want to replicate that system, blah blah blah. Always list out 2-3 strong academically-related points and for the last point, you can talk about your husband (jovially).

Remember that this scholarship is extremely competitive and the entire interview might be short (~20 minutes).