Below are given some sentences out of which the sentence numbered 4 has been correctly placed. The rest of the sentences A, B, C, D, E, F need to be arranged correctly in order to form a logical order. 

A. He launched a bloody and destructive campaign against the state of Kalinga on the east coast.

B. Ashoka was an Indian emperor of the Maurya Dynasty.

C. He established schools and hospitals for the poor and built many Buddhist temples across the Indian sub-continent.

4. However, after witnessing the aftermath of the destructive war he became aware of the great suffering he had caused.

D. After his conversion to Buddhism, he forsook his wars of conquest and became devoted to the Buddhist principles of non-violence.

E. His remorse caused him to completely change course and embrace Buddhism.

F. In this campaign, Ashoka’s army killed many thousands of people.