_____ country won gold medal in all the 4 events in the 24th edition of ITTF (International Table Tennis Federation) World Tour Hong Kong open ?

1) China
2) Japan
3) South Korea
4) North Korea

Explanation:
The 2019 Hong Kong Open, a part of the 24th edition of ITTF (International Table Tennis Federation) World Tour was held from 6th to 9th June 2019 at Queen Elizabeth Stadium in Hong Kong. The prize money of the tournament was USD 175000. It comprises Men’s single & doubles and Women’s singles & doubles. Hong Kong Open was first held in 2018.China claimed four gold medals at the tournament.