Trey has two dependents, his daughters, ages $14$ and $18,$ at year$-$end. Trey files a joint return with his spouse.

What amount of child tax credit $($either as a child or a qualifying dependent$)$ will Trey be able to claim in $2023$ for his daughters under each of the following alternative situations? Use Exhibit $8-8.$

b$.$ His AGI is $$420,000.$