It is hard to believe that they don't even have a single clue on what you asked unless they just only knew few things about crypto but not a total crypto enthusiast at all (Probably).
Anyway, my guess is anything related to food industry such as convenient stores, restaurants and fast food chains.
Only one of them knows about cryptocurrency. The others didn't hear about it until that night. Frankly I think they are not sure they understand crypto at that time, hence the silence.
I was surprised you said the food industry. I was expecting more like the ones that pays big, like the ones I mentioned above.
Telecommunications companies i think, Imagine almost all people have their own mobile and gadgets used daily, either in a way of communicating, surfing gaming, streaming & etc. all of these activities consumes data. What if one telcos company adopt a blockchain Technology and tokenize its platform??
I guess this makes sense, but I wonder if the cost of the data will be more expensive once it starts running on blockchain?