Sergio and Sally have a very diverse family. Which of the following children would not be a qualifying child for the purpose of claiming the child tax credit in 2023?
a) Their 7-year-old niece whom they support financially
b) Their 16-year-old son who lives with them
c) Their 20-year-old daughter who is a full-time college student
d) Their 3-year-old son who lives with them
