I think this question is a good place to demonstrate your thought process rather than commercial awareness. Just ensure you have solid reasons for why you'd like the law introduced and what you expect its impact to be.
My perspective on this is slightly different to @AvniD's. I think it could be a means to demonstrate commerciality/commercial thinking as well as more general thoughtfulness. Alternatively, you could interpret this as an invitation to introduce an interest in something that you think requires regulation (i.e., the topic definitely does not have to be commercial).
This question is trying to provoke you into a reasoned discussion about a topic using a legal lens. It is trying to provoke creativity and original thought. So long as you can pick an area and an appropriate law in a justified, well-reasoned way, you are good to go!
For what it's worth, here's quote by Locke to think about: "where there is no law, there is no freedom". When I was asked this question, I was reminded of it! It demonstrates that it is not necessary for a law to be primarily about restricting behaviour. Laws can also act to enable or facilitate activity.
Hope that might help to provoke some thoughts on this for you