Complex sentence: In 1967, he was defeated at Arambagh by another Gandhian, Ajoy Mukherjee, who became Chief Minister of West Bengal after Prafulla Chandra Sen. The Architect of Ajoy Mukherjee's victory at Arambagh was Narayan Ch Ghosh, the then student leader.
Split into simpler sentences: In 1967, he was defeated at Arambagh by another Gandhian, Ajoy Mukherjee, who became Chief Minister of West Bengal. The architect of Ajoy Mukherjee's victory at was Narayan Ch Ghosh, the then student leader.