Which of the following interest-free loans are subject to the imputed interest rules?

a. Alamor Corporation loans Sandy, an employee, $8,000. The loan is to be repaid over 4 years. Sandy uses the proceeds to buy a used automobile. She has $1,100 in investment income during the current year.

b. Trinh loans her son Jimmy $80,000. The loan is to be repaid over 20 years. Jimmy uses the loan to purchase a cabin in the mountains. He has $300 in investment income during the current year.

c. Abdula Corporation loans Augie, an employee, $80,000. The loan is to be repaid over 20 years. Augie uses the loan to purchase a new house. He has $300 in investment income during the current year.

d. Isabel owns 10% of Marcos Corporation. Isabel loans Marcos $20,000 to use for working capital. The loan is to be repaid over 5 years. Marcos has no investment income during the current year.

e. Stuart loans his sister Sima $120,000. The loan is to be repaid over 20 years. Sima uses the loan to purchase a new home. She has no investment income during the current year.