Final answer:
The first step in photosynthesis is (Choice B) Chlorophyll capturing light energy, which happens before energy is used to build sugars or chemical energy is released from sugar molecules.
Step-by-step explanation:
This step is fundamental because chlorophyll in the chloroplasts absorbs the sunlight that initiates the process of photosynthesis. This absorbed light energy excites electrons, leading to a chain of reactions that ultimately convert light energy into chemical energy stored in ATP and NADPH during the light-dependent reactions. These energy carriers are then used in the Calvin cycle to build sugars from carbon dioxide and water. Hence, the correct answer to the question is Chlorophyll captures light energy. The first step related to the energy transformation during photosynthesis is Chlorophyll captures light energy.