To answer the question of who is the only Judge of the Supreme Court of India to also have been the Vice-President of India, we need to review the options provided:
- Justice A. N. Ray
- Justice Mohammad Hidayatullah
- Justice Patanjali Sastri
- Justice P. N. Bhagwati
Justice Mohammad Hidayatullah served as the Chief Justice of India from 1968 to 1970. After his tenure in the judiciary, he was appointed as the Vice-President of India, serving from 1979 to 1984. During his term as Vice-President, he also served as the ex-officio Chairman of the Rajya Sabha. None of the other Justices listed held the position of Vice-President of India.
Therefore, the correct answer is Justice Mohammad Hidayatullah.