The poster has not been given in the question and is also not found anywhere else but based on the knowledge of coal formation the correct option can be predicted.
Answer: Sunlight shinning on Earth (Option D)
Explanation:
Coal formation takes place inside the earth. It takes hundreds of years for its formation. The plant and animal debris under extreme temperature and pressure gets converted into coal which is extracted and used as source of energy.
Adding a sun in the poster can help to show the growth of plants which helps the growth of animals as well. Plants make food that is consumed by animals. When these plants and animals die, they are buried or gets buried inside the earth.
This is how the process of coal formation starts and hence, the correct answer would be option D.