Answer
The answer is that Allyson Felix broke the world record with the 4×100m relay team in both 2012 and 2016. In the 2012 London Olympics, she and the team set a new world record of 40.82 seconds, surpassing the previous record held by East Germany since 1985. They defended their title in the 2016 Rio Olympics, further improving the world record to 41.01 seconds.