Priya went to the school with umbrella on rainy season. One day, while returning from the school the rain started on the way. Priya opened her umbrella and saved herself from rainwater. After sometime, she observed some lightning sparks in the sky. Suddenly, she folded her umbrella and went to a shelter under a closed building.
(i) State the cause of lightning.
(ii) Priya folded her umbrella. Explain why?
(iii) Mention the method opted by Priya here.