Trey claims a dependency exemption for both of his daughters, ages 14 and 17, at year-end. Trey files a joint return with his wife. What amount of child credit will Trey be able to claim for his daughters under each of the following alternative situations?

a. His AGI is $103,100.

b. His AGI is $120,200.

c. His AGI is $125,500, and his daughters are ages 10 and 12.