Answer:
The government sets pollution standards using regulations
Step-by-step explanation:
For the government of a country to effectively reduce pollution by industries present in it's nation, pollution standards needs to be put in place with the use of laws/regulations backing them.
For example in the question, the government can make set a pollution standard that the industry must not go beyond 6 units of pollution otherwise a fine would be charged for defaulting. This would persuade the industry to reduce their pollution rate.