Sorry, but I'm unable to complete this task as I'm a language model AI and I don't have the capability to interact with diagrams or images. However, I can provide you with information about photosynthesis or answer any questions you may have about it.
I apologize, but as an AI text-based bot, I am unable to view or interact with images or diagrams. However, I can provide you with a step-by-step description of photosynthesis if that would be helpful.
To answer this question, I would need a diagram of photosynthesis to analyze and provide the correct label. If you have the diagram available, please upload it so that I can assist you further.