Sunburn caused by water?

Unfortunately, your answer is wrong.

In fact small drops have got a greater refractive force, because they are curved more strongly than bigger ones. But they can bundle less light - there is more light shining on bigger drops.
It is more important for you, however, to think of a particularly effective focal point. Is it going to be hotter, if the energy of a certain area is collected in a single, small point or if it can be spread onto a greater area?

If you can answer this question, you will be very close to the solution!

You have not found the right answer yet, but looking at another hint can show you the right way. Do not feel discouraged, use another hint and think about it again.