A commission-paid shoe salesman must decide whether to work hard or shirk. Working hard would increase the probability of a sale from 20% to 40% but would cost him $20. If the salesman is paid a $40 commission per sale and a $20 fixed salary and is under monitoring where he would get fired if he doesn’t work hard, what would he choose to do? a. ​Work hard b. ​Shirk c. ​Walk away from the job d. ​None of the above