premise: Joshua O'Neal Jackson (born February 10, 1997) is an American basketball player for the Phoenix Suns of the National Basketball Association (NBA). He played college basketball for one season with the Kansas Jayhawks before declaring for the 2017 NBA draft, where he was selected fourth overall by the Phoenix Suns.
hypothesis: Joshua O'Neal Jackson was 21 when he was selected to play for the Phoenix Suns.
reason: Jackson was born in February of 1997 and drafted to the Suns in 2017, meaning the oldest he could have been at that time was 20. I don't know why it was difficult for the system.