Marianne and Laura Are Both Homemakers with Children

Marianne and Laura are both homemakers with children.Then Laura takes an unpaid volunteer job at a hospital and hires Marianne to care for her preschool-age child.What happens to GDP?  

A)  GDP increases. 
B)  GDP decreases. 
C)  GDP does not change. 
D)  GDP increases only if Marianne gives the child better care than Laura does.