Which of the Following Increases GDP

Multiple Choice

Which of the following increases GDP?  

A)  Workers take more vacation time. 
B)  The length of the average work week decreases. 
C)  Homeowners purchase lawn-care services rather than doing the lawn maintenance themselves. 
D)  Meals cooked at home at an average cost of $10 each are replaced by restaurant meals at an average cost of $10 each.