Raising Cattle Causes Negative Externalities in the Form of Gas

Multiple Choice

Raising cattle causes negative externalities in the form of gas and manure produced by cows, which contains methane, a greenhouse gas that causes climate change. Suppose the government is developing a policy to counteract this externality. Which of the following is a policy that directly targets the externality?

A) A tax on methane emissions
B) A tax on cow purchases
C) Tradeable permits where each allowance is for one cow
D) All of these are policies that target the externality.