"On our copy of the tax return we noticed that we were not able to claim all of our children as dependents. Why would that be? I guess we are not sure what qualifies us to claim them and wondered why we couldnt just list them all and hope that no one notices."

During 2018, Dan and Freida furnished over half of the total support of each of the following individuals, all of whom still live at home:

1. Gina, their daughter, age 22, a full-time student, who married on December 21, 2018, has no income of her own and for 2018 did not file a joint return with her husband, Casey, who earned $10,600 during 2018. Gina's Social Security number is 123-45-6788.
2. Willie, their son, age 20, who had gross income of $6,300 in 2018, dropped out of college in October 2018. He had graduated from high school in May 2018. Willie's Social Security number is 123-45-6787.
3. Ben, their oldest son, age 26, is a full-time graduate student with gross income of $5,200. Ben's Social Security number is 123-45-6786.

Why was Ben not eligible to be claimed?