During photosynthesis, the light energy is captured by the chlorophyll and this energy is used in the formation of sugar molecules with the help of water. Oxygen is released as the byproduct of this process.
So the light energy which is captured is stored in the bonds of sugar and when this bond is broken down during oxidation the energy is released and converted into another form which is ATP and this ATP is called the energy currency of the cell. This ATP is used in many metabolic processes. Therefore the correct answer is sugar.
