Task: Question Generation
Input (English): Background Paragraph: The Gaia hypothesis states that the biosphere is its own living organism. The hypothesis suggests that the Earth is self-regulating and tends to achieve a stable state, known as homeostasis . For example the composition of our atmosphere stays fairly consistent, providing the ideal conditions for life. When carbon dioxide levels increase in the atmosphere, plants grow more quickly. As their growth continues, they remove more carbon dioxide from the atmosphere. In this way, the amount of carbon dioxide stays fairly constant without human intervention. 
Story: Two friends had a discussion about the Earth and what this reality might be. Tim believed in  the Gaia hypothesis, while Olly  believed in the Panspermia theory.
Output (English): Which friend believed that the Earth tends to achieve a stable state?