What would a marginal benefit / marginal cost graph look like if zero pollution was the optimal level? (Multiple answers allowed)
1. The marginal cost and marginal benefit curves intersect on the y-axis
2. The marginal benefit curve is always above the marginal cost curve and the distance among them is growing
3. The marginal benefit curve is always above the marginal cost curve and the distance among them is constant
4. The marginal cost curve is always above the marginal benefit curve and the distance among them is growing
5. The marginal cost curve is always above the marginal benefit curve and the distance among them is constant