to change oxygen into carbon dioxide to break down sugar into usable chemicals to convert energy from sunlight into food energy to allow the passage of carbon dioxide into the plant
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: What is the main function of photosynthetic cells within a plant?
Possibilities:
- to change oxygen into carbon dioxide
- to break down sugar into usable chemicals
- to convert energy from sunlight into food energy
- to allow the passage of carbon dioxide into the plant

to convert energy from sunlight into food energy