All who use fire have intelligence. 1 is wrong. Please try again. Some cave dwellers use fire. All who use fire have intelligence.
Some cave dwellers use fire.
All who use fire have intelligence. If SOME of them use fire, and ALL who do this have intelligence, then SOME of them have intelligence. It might be that they ALL have intelligence. But we can't conclude this from the premises, since we only know that SOME of them use fire. 3 is wrong.