Sammy is taking notes to study for a test. He wrote out the steps that involve hydrogen during photosynthesis. The steps are shown, but they are not in the correct order. 1- water is broken down into oxygen and hydrogen.
2- Glucose is broken down to be used by plants.
3- hydrogen combines with carbon dioxide to form glucose.
4- Hydrogen enters the plant as part of water.

Which lists the correct order of the steps?

• 4, 2, 1, 3
• 4, 1, 3, 2
• 4, 3, 1, 2
• 4, 2, 3, 1