A manager is trying to decide whether to buy one machine or two. If only one machine is purchased and demand proves to be excessive, the second machine can be purchased later. Some sales would be lost however, because the lead time for delivery of this type of machine is six months. In addition, the cost per machine will be lower if both machines are purchased at the same time. The probability of low demand is estimated to be 0.30 and that of high demand to be 0.70. The after-tax NPV of the benefits from purchasing two machines together is $90,000 if demand is low and $170,000 if demand is high. If one machine is purchased and demand is low, the NPV is $100,000. If demand is high, the manager has three options: (1) doing nothing, which has an NPV of $100,000; (2) subcontracting, with an NPV of $140,000; and (3) buying the second machine, with an NPV of $120,000 a. Choose the correct decision tree for this problem. Note that each payoff is given in thousands of dollars. O A. O B. Low demand Low demand Buy 1 90 Do nothing 100 Q Buy 1 100 2 0.30 Do nothing machine High demand Subcontract 140 [ machine 100 High demand Subcontract Low demand Buy 2 120 2 140 Buy 2 100 machines 0.70 Buy 2 Buy 2 120 3 machines machines High demand machines Low demand 170 90 0.30&C. O D. Low demand 100 Do nothing Low demand Buy 1 0.30 100 Buy 2 100 Do nothing 0.70 100 machine High demand Subcontract High demand Subcontract 2 140 machines 140 0.70 2 Buy 2 0.30 Low demand 120 Buy 2 Low demand 120 Buy 2 0.30 90 machines Buy 1 0.70 90 machines machines High demand 170 machine High demand 170 0.70 0.30 b. What is the best decision and what is its expected payoff? Best decision is to buy machine(s) and its expected payoff is $ . (Enter your responses as integers.)