Answer: C. inefficiently low; inefficiently high
Step-by-step explanation:
If the cotton farmers are not made to pay for the damage that their pesticides cost then they will maintain production at a relatively high level because their input costs will be relatively low. As a result of this high level of production, the price of the goods will be relatively low as well. The point at which both market equilibrium quantity and price are at in this scenario are considered inefficient because they are not taking into account, the true cost of production being the effects of the pesticides being used.
However, if they are made to pay for this negative externality that they are the cause of, it will increase their production cost and force them to reduce production to keep these costs low. As they reduce production, the market price will increase as supply is less.