Final answer:
The most radical deputies who seized the leadership of the Estates General and converted it into the National Assembly were lawyers and other professionals who represented the Third Estate.
Step-by-step explanation:
The most radical deputies who seized the leadership of the Estates General and converted it into the National Assembly were lawyers and other professionals who represented the Third Estate. The Third Estate was made up of commoners, which included educated merchants and large landowners. They gained support from sectors of the clergy and nobility to declare themselves as the National Assembly and formed a new government.