What did the ancient people know & think about lightning?

Ancient people think that lightning is the wrath of God.
Lightning was thought to be Zeus' weapon by the ancient Greeks. Minerva, the goddess of wisdom, invented thunderbolts. Because lightning was a sign of the gods, any location struck by lightning was considered sacred. In ancient times, due to the lack of knowledge, people felt afraid of lightning and thought it was God's anger.
Hence, the correct option is the "wrath of God".