Answer: Option A
Explanation:
The X label shows the plants( producers) which undergoes photosynthesis. Photosynthesis is a biological process by which the plants make food by the help of the carbon dioxide and water in the presence of sunlight and release oxygen as a by product and glucose as a product.
The Y label shows decomposers that return carbon to the soil and release waste. The waste is dead and decaying remains of the plants and animals that is decomposed by decomposers and releases carbon into environment.
hence option A is correct.