Consider the following scenario: There are two products X and Y that are being manufactured. As a part of the process, both X and Y need to be processed on a machine which has 100 hours available. Each product X and Y needs 2 hours for each unit. Which of the following constraints would fully specify this restriction in an optimization model? (please choose one below)

• X ? 100 and Y ? 100
• X + Y ? 100
• 2X + 2Y ? 100
• None of the above