Carol owns a small curio shop that is incorporated as an S corporation. Her three children, Sara, age 16, Mark, age 19, and Corey, age 22, all help in the shop. Which of the children's wages are subject to FICA taxes?
1. None of the wages are subject to FICA taxes.
2. Corey's wages only.
3. Mark and Corey's wages only.
4. All their wages are subject to FICA taxes.