Which one of the following would be included in the calculation of GDP by the expenditure approach?

Select one:

a.the purchase of an original eighteenth century work of art

b.the purchase of 20 shares of a new issue of IBM stock

c.the value of your brother's services when he mows the lawn for the family

d.the income you pay to your gardener

e.the cost of adding a new kitchen to your house

Why is the answer adding a new kitchen to your house? Is the art purchase on an investment? Is the purchase of stocks not an investment?