Niles and Marsha adopted an infant boy (a US citizen). They paid $15,500 in 2020 for adoption-related expenses. The adoption was finalized in early 2021. Marsho received $4,000 of employer-provided adoption benefits. For part (4), assume that any adoption credit is not limited by modified AGI or by the amount of tax liability Required: a. What amount of adoption credit, if any, can Niles and Marsha take in 2021? b. Using the information in part (a), assume that their modified AGI was $223,000 in 2021. What amount of adoption credit is allowed in 2021? Note: Do not round Intermediate calculations, Round your final answer to the nearest whole dollar amount. Amounts a Amount of adoption credit Amount of adoption credit