Windmills are expensive to build. The wind does not blow all the time. Pollution is not created by windmills. Populations of birds can be reduced by windmills.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Windmills are used to obtain usable energy from wind. Which would be an advantage of using a windmill?
Possibilities:
- Windmills are expensive to build.
- The wind does not blow all the time.
- Pollution is not created by windmills.
- Populations of birds can be reduced by windmills.

Pollution is not created by windmills.