In 2018, Irene, an unmarried individual, pays $6,500 in qualified adoption expenses to an adoption agency for the final adoption of an eligible child who is not a child with special needs. In the same year, the individual’s employer, under a qualified adoption assistance program, pays an additional $4,000 for other qualified adoption expenses to an attorney on behalf of Irene for the adoption of the child. Assuming Irene is not subject to the phase-out, she may exclude, from her personal income, how much of the $4,000 payment made by her employer? 

a. $6,500 

b. $5,000 

c. $4,000 

d. $0