The correct order is:
4 - Hydrogen enters the plant as part of water.
1 - Water is broken down into oxygen and hydrogen
3 - Hydrogen combines with carbon dioxide to form glucose.
2 - Glucose is broken down to be used by plants.
Step-by-step explanation:
Photosynthesis is a chemical process whereby plants produce carbohydrates from solar radiation, water (H2O), and carbon dioxide (CO2). These carbohydrates produced by photosynthesis, especially monosaccharides (glucose and fructose), are stored as a source of energy to be used later in different functions including plant growth and development.