Suppose the Market Wage for Cashiers Increases from $7 Per

Suppose the market wage for cashiers increases from $7 per hour to $9 per hour. As a result, Pat, who is a cashier, now works five more hours per week. On the other hand Chris, who is also a cashier, now works five fewer hours per week. Chris's behavior illustrates the ________ effect of a wage increase.

A) demand
B) supply
C) income
D) substitution