Explanation:

- Shaili Singh: ?? The correct answer. Shaili Singh won the silver medal in the women's long jump event at the U-20 World Athletics Championships in August 2021. She is a promising athlete from India.

- Nayana James: An accomplished Indian long jumper, but there is no record of her winning a medal at the 2021 U-20 World Championships.

- MA Prajusha: An Indian athlete specializing in long jump and triple jump. She didn't compete in the 2021 U-20 championships.

- Reeth Abraham: A former Indian long jumper, but she was not the one who won a medal at the U-20 World Championships in 2021.