The correct answer is option 4, Naomi Osaka. In the second round of the French Open Tennis Tournament 2021, Naomi Osaka withdrew from the competition due to a controversy regarding media obligations.

Naomi Osaka, a professional tennis player from Japan and a four-time Grand Slam champion, had previously announced that she would not participate in the traditional post-match press conferences during the tournament, citing mental health concerns. This decision was met with mixed reactions from both the public and tennis officials, with some supporting her stance while others raised concerns about the responsibilities of athletes.

As a result of this controversy, Naomi Osaka made the difficult decision to withdraw from the tournament after her first-round victory. In a statement on social media, she shared her struggles with depression and anxiety and expressed the need for a change in the way athletes are required to interact with the media.

It is important to note that while the other options listed (Coco Gauff, Serena Williams, and Ana Bogdan) are all renowned tennis players, they did not withdraw from the French Open in 2021 due to media obligations.