Explanation:

- Manpreet Singh: An Indian field hockey player who was part of the team that won a bronze medal at the 2020 Tokyo Olympics. He was awarded the Major Dhyan Chand Khel Ratna Award in 2021.

- Sumit Antil: A para-athlete who won a gold medal in javelin throw at the 2020 Tokyo Paralympics. He was honored with the Major Dhyan Chand Khel Ratna Award in 2021.

- Krishna Nagar: Another para-athlete who clinched a gold medal in badminton at the 2020 Tokyo Paralympics and was also a recipient of the Major Dhyan Chand Khel Ratna Award in 2021.

- Mandeep Singh: This option is correct as Mandeep Singh, a field hockey player, was not listed among the awardees of the Major Dhyan Chand Khel Ratna Award in 2021.

Correct Answer: Option 4 - Mandeep Singh