Usman anticipates having some spare time during the coming summer and is considering four options. To determine the best option, he estimates the revenues and the costs associate with each option: Option 1- Revenue: $2,500, cost: $700; Option 2-Revenue: $5,000, cost: $3,800; Option 3-Revenue: $1,700, cost $250; Option 4(charity work)-Revenue $0, cost $400. Required: a. Based only on estimated revenues and costs, what is the value of each of the four options? b. Based only on estimated revenues and costs, what is the opportunity cost of each of the four options? c. Based only on estimated revenues and costs, identify the option for which the value is greater than the opportunity cost. d. What benefit is Usman implicitly attaching to doing charity work if he chooses Option 4? (10 points)