Answer:
Due to Chauri Chaura incident.
Step-by-step explanation:
The non cooperation movement withdraw due to Chauri Chaura incident where 22 policemen were burnt alive. Mahatma Gandhi is the person who decided to withdraw the movement because he felt that satyagrah is needed to be trained properly for mass movement in the future in order to prevent violence in mass movement. Mahatma Gandhi was arrested as well as followed by the arrest of other leaders.