Which choice avoids run-on sentences to present the information clearly and correctly?

Levi wanted to save the endangered sparrows, he built a birdhouse and he passed out flyers and he also hung signs to tell people to keep their cats inside.

Levi wanted to save the endangered sparrows. He built a birdhouse, and he passed out flyers. He also hung signs to tell people to keep their cats inside.

Levi wanted to save the endangered sparrows. He built a birdhouse, and he passed out flyers he also hung signs to tell people to keep their cats inside.

Levi wanted to save the endangered sparrows, so he built a birdhouse. He passed out flyers, he also hung signs to tell people to keep their cats inside.