The sun causes evaporation.
The answer is - c. serving in the military.
Just to be clear, serving in the military is not forbidden for Israeli Arabs, but it is the only thing that is not ''required'' of them to do. Israelies have to go to military service, while Israeli Arabs are not ''required'' to do that. Even though most of them don't do it, still there's the occasional exception where some of them want to go to military service and they do attend it.
Solid
Naturally occurring
Definite chemical composition
Inorganic
Definite crystalline structure
