Missing Part of Question:
The related graph was not present with the original question, so I am attaching it here.
Explanation:
[tex]Q_{E} \;=\;Equilibrium\;Quantity\\[/tex]
(a) In a free market, at a quantity exactly equal to [tex]Q_{E}[/tex], the value of a unit to a buyer is equal to the cost of a unit to a seller. For a quantity below [tex]Q_{E}[/tex], the value of unit to a buyer is greater than the cost of that product to the seller. Finally, for a quantity above [tex]Q_{E}[/tex], the value of that unit to the buyer is less than the cost incurred by the seller.
(b) The dumping of toxic chemicals is a typical scenario of Negative Externality which may lead to Market Failure due to poor display of supplier reputation.
