Jennifer uses the cash method. Which of the following transactions result in gross income in the current year?

a. Car, worth $7,000, received as a consulting fee

b. $500 of interest credited to her checking account, but not withdrawn

c. Wages payable from a corporation with ample funds, in which she is a 12 percent shareholder, unpaid at year-end

d. Stock, worth $20,000, for services rendered, fully vested if Jennifer still works for the corporation in three years

e. $700 of dental services (bill cancelled upon Jennifer's estate planning advice to the dentist's mother-in-law)

f. Sale of a used car for a note due in one year, face value $3,000, fair market value

$2,500. No elections were made.