A Mother Has Been Paying Her Daughter Melissa One Dollar

A mother has been paying her daughter Melissa one dollar an hour to shovel snow off the driveway. At the end of January, the mother raises the rate to two dollars an hour. Based on research related to contrast effects, we can predict that Melissa will probably:

A) Shovel half as much snow as she would have otherwise, and then she'll quit.
B) Shovel the same amount of snow as she would have at a dollar-an-hour rate.
C) Shovel less snow than if the pay for shoveling snow had always been two dollars an hour.
D) Shovel more snow than if the pay for shoveling snow had always been two dollars an hour.