Which of these cases would be subject to the "kiddie tax"?

Mina, age 12, earned $800 in dividends, with no other income.

Jordan, age 15, worked as a lifeguard all summer and earned $2,800 with no other income.

Bophy, age 14, earned $1,000 in interest and had a $1,800 royalty from a family oil well. She had no other income.

Victor, age 19, is taking a year off before starting college. He received $4,200 in dividends with no other income.