The correct answer is option 2, Neelam Sanjiva Reddy. He was elected unopposed as the President of India.

Option 1, Dr Rajendra Prasad was the first President of India, but he was not elected unopposed. He was elected by a vote in the Constituent Assembly.

Option 3, Gyani Jail Singh was the seventh President of India, but he was also not elected unopposed. He was elected by Parliament.

Option 4, Pratibha Patil was the first woman President of India, but she was not elected unopposed. She was elected through a vote by members of the Electoral College consisting of Members of Parliament and State Legislative Assemblies.

Therefore, option 2 is the correct answer as Neelam Sanjiva Reddy was indeed elected unopposed as the President of India.