Indicate whether each of the following was counted in the United States gross domestic product for the year 1998. Explain each of your answers.

a) The commission earned by a Realtor who sold a house in 1998. The house was originally built in 1955.

b) The value of an automobile produced in 1998, but sold on January 1st, 1999.

c) The $1000 that Kevin earned from a stock that he bought and sold in 1998.

d) The value of blenders produced in 1998 entirely in Germany by a company that is owned by American citizens.