5 September is celebrated as –

National Youth Day
National Army Day
National Teachers' Day
National Water Day

The correct answer is: National Teachers’ Day.

National Teachers’ Day is celebrated on 5 September in India to commemorate the birth anniversary of Dr. Sarvepalli Radhakrishnan, the second President of India. He was a renowned scholar, philosopher, and teacher. He was also the first Vice President of India.

Dr. Radhakrishnan was born on 5 September 1888 in Tiruchirappalli, Tamil Nadu. He was educated at the University of Madras and the University of Oxford. He was a professor of philosophy at the University of Calcutta and the University of Mysore. He was also the Vice-Chancellor of the University of Delhi.

Dr. Radhakrishnan was a great scholar and philosopher. He wrote many books on philosophy and religion. He was also a great teacher. He inspired many students and helped them to achieve their goals.

National Teachers’ Day is a day to celebrate the contributions of teachers to society. It is a day to thank teachers for their hard work and dedication. It is also a day to encourage students to respect and appreciate their teachers.

The other options are incorrect because:

  • National Youth Day is celebrated on 12 January.
  • National Army Day is celebrated on 15 January.
  • National Water Day is celebrated on 22 March.