Answer:
Substance A is water and Substance B is chlorophyll.
Step-by-step explanation:
Photosynthesis is a process which occurs mainly in plants in which inorganic substances like carbon dioxide (CO2) and water (H2O) combine to form organic substance named as glucose (C6H12O6) which is a sugar. But in order for CO2 and H2O to react with each other energy is required. The source of this energy is sunlight which is captured by a pigment named as chlorophyll which is present in an organelle named as chloroplast of plant cell.