In connection with the adoption of an eligible child who is a U.S. citizen and who is not a child with special needs, Sean pays $4,000 of qualified adoption expenses in 2017 and $3,000 of qualified adoption expenses in 2018. The adoption is finalized in 2018. There is no phase-out of the adoption credit. What are the adoption credits for both 2017 and 2018, respectively? 

a. $0; $7,000 

b. $4,000; $1,000 

c. $4,000; $3,000 

d. $7,000; $0