Hi There I have economics homework and I am really Struggling. Would love an explanation. I have provided reference figure as attatchment

Question 4: Externalities

Many observers believe that the levels of pollution in our economy are too high.

a) If society wishes to reduce overall pollution by a certain amount, why is it efficient to have

different amounts of reduction at different firms?

b) Command-and-control approaches often rely on uniform reductions among firms. Why are

these approaches generally unable to target the firms that should undertake bigger

reductions?

c) Economists argue that appropriate corrective taxes or tradeable pollution rights will result in

efficient pollution reduction. How do these approaches target the firms that should undertake

bigger reductions?

Question 6 - Topic: Public goods and Common Resources

Four types of goods Rival In consumption Yes No Private goods Club goods - Ice-creams - Fire protection - Clothing - CableTV - Congested toll roads - Uncongested toll roads Excludable? Common resources Public goods - sh in the ocean - National defence 0 The environment 0 Knowledge - Congested nontoll roads - Uncongested non-toll roads Goods can be grouped into four categories according to two questions: [1] Is the good excludable? That is. can people be prevented from using it? [2] Is the good rival? That is. does one person's use of the good diminish other people's use of it? This figure gives examples of goods in each of the four categories