Assertion (A) states that in photosynthesis, solar energy is converted into chemical energy and stored in food. This is fundamentally correct. Reason (R) states that the final product is glucose, which turns into starch. Glucose is indeed the primary sugar produced, and it is then converted to starch for storage. This process also supports the energy conversion mentioned in the assertion. Therefore, both are true, and the reason correctly elaborates on the mechanism of energy storage in photosynthesis.