The correct answer is B. Virginia Thrasher. She was 16 years and 300 days old when she won the gold medal in the 10m air rifle event.
Deepa Karmakar was 22 years and 103 days old when she competed in the vault event. Gaurika Singh was 18 years and 259 days old when she competed in the 100m freestyle event. Emily Seebohn was 22 years and 113 days old when she competed in the 100m backstroke event.
Virginia Thrasher was born on December 13, 1998, in Springfield, Virginia. She started shooting when she was 8 years old. She won the gold medal in the 10m air rifle event at the 2016 Summer Olympics, becoming the youngest American to win an Olympic gold medal in shooting. She also won the gold medal in the 10m air rifle event at the 2015 Pan American Games.