Sure! Here are the correct options based on the text provided:

1. **Which is a big problem in the city?**
- **D. Both A & B are correct.** (Traffic jams and pollution)

2. **What causes traffic jams in the city?**
- **A. too many cars on the roads**

3. **How can cities reduce traffic congestion according to the passage?**
- **C. by promoting the use of public transportation**

4. **What is suggested as a solution for pollution in cities?**
- **B. planting more trees and creating green spaces**

5. **What do trees provide?**
- **C. oxygen and clean air**

6. **Which sentence is TRUE according to the passage?**
- **D. To avoid traffic jams, people should use public transport.**

If you have any further questions or need clarification, feel free to ask!