Answer:
This is an essay question, so you'll need to write a paragraph at least, depending on how long of an answer you're required to give.
I'm sure you have probably experienced something that you wish was different in the world. The first thing that comes to my mind is the current pandemic. You could briefly write that you wish that the pandemic had not happened and killed the amount of people it has. Or you could write that you wish there was a cure.
You could also wish that cars hadn't been invented, or a war didn't happen.
Good luck!