The correct answer is D.
Explanation:
1. Photosynthesis is a chemical process carried out by autotrophs (organisms that can produce their own food) like plants, algae, and some bacteria.
2. During photosynthesis, these autotrophs convert inorganic substances (such as carbon dioxide and water) into organic substances (like glucose) using sunlight as an energy source.
3. This process is crucial for the production of food and oxygen in the ecosystem.
4. Ron should elaborate on this point as it is a fundamental aspect of photosynthesis and explains how plants and other autotrophs sustain themselves and contribute to the ecosystem's balance.
In conclusion, Ron should focus on elaborating on the chemical process of photosynthesis by autotrophs converting inorganic substances into organic substances using sunlight as an energy source.