Explain what happens to contributions to GDP in each of the following situations.
a. A woman who makes a living charging for investment advice on her Internet Web site marries one of her clients, to whom she now provides advice at no charge.
b. A man who had washed the windows of his own house every year decides to pay a private company to wash those windows this year.
c. A company that had been selling used firearms illegally finally gets around to obtaining an operating license and performing background checks as specified by law prior to each gun sale.