William is developing the model shown below to illustrate the process of photosynthesis. He plans to use the model to explain how photosynthesis transforms both energy and matter.

The diagram shows a chloroplast. In the light-dependent reactions, light strikes the thylakoids, water enters, and oxygen is released. In the light-independent reactions, carbon dioxide enters a cycle and sugars leave the cycle.

The model includes a wavy arrow to show light striking the thylakoids. Which label for the wavy arrow would be MOST USEFUL for communicating the role of light in photosynthesis?

A. Light is radiated from the chloroplast during the light-independent reactions.
B. Light energy is cycled within the thylakoid.
C. The chloroplast reflects the green wavelengths of light.
D. Light is the energy source for converting ADP to ATP, and NADP+ to NADPH.