Answer: Option [D]
Dr. Rajendra Prasad was elected as the first President of India by Constituent Assembly. When India became a republic in 1950, Prasad was elected its first president by the Constituent Assembly. From 1946 to 1949 he presided over the Indian Constituent Assembly and helped to shape the constitution. He was unanimously elected president in 1950 and, after the first general election (1952), was chosen by an overwhelming majority of the new electoral college; in 1957 he was elected to a third term.