as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
brainstorm 3 possible solutions to the following problem: 

pollution levels in a heavily populated city have increased.
user
1. subsidize public transportation to reduce the number of cars on the road. 
2. incentivize businesses to switch to renewable energy sources.
3. implement stricter regulations on industrial pollution.
assistant