The first President of India, who was also the longest-serving President, was:

Rajendra Prasad. Dr. Rajendra Prasad was the first President of India, taking office when the Constitution came into force in 1950. He served for about twelve years, the longest of any President, and is the only President to have been elected twice.

His tenure:

• He was first elected by the Constituent Assembly as President in January 1950.
• He was elected in the first presidential election in 1952 and was later re-elected for a second term.

Early life:

• He was born on 3 December 1884 at Ziradei in Bihar.
• He was a brilliant student and a successful lawyer.

Role in the freedom struggle:

• He joined Mahatma Gandhi in the Champaran Satyagraha of 1917.
• He took part in the Non-Cooperation, Civil Disobedience and Quit India movements and was imprisoned several times.
• He was President of the Indian National Congress three times.

Role in the Constituent Assembly:

• He was the President of the Constituent Assembly.
• He chaired important committees, such as the Steering Committee and the Rules of Procedure Committee.

As President of India:

• He set many conventions for the office.
• He had some differences with Prime Minister Nehru, for example on the Hindu Code Bill, but generally acted on the advice of the government.
• He travelled widely as a goodwill ambassador.

Writings:

He wrote "India Divided" and his autobiography, "Atmakatha".

After retirement:

He lived at Sadaqat Ashram in Patna until his death in 1963.

Popular name:

He was affectionately called "Rajendra Babu" and "Deshratna".

Why not the other options?

Dr. S. Radhakrishnan was the second President.

Dr. Zakir Husain was the third President.

• Rajagopalachari was the last Governor-General, not President.