Consider a firm Theta that spends $60 to produce goods in year 1. In year 2 it sells these goods for $100, but its customers pay their bills with a delay, therefore the payment is not received until year 3. What's the amount of net working capital for each year?

year 1: $60; year 2: $100; year 3: $0

year 1: -$60; year 2: $100; year 3: $0

year 1: -$60; year 2: $0; year 3: $100

year 1: $60; year 2: $40; year 3: $0