Chlorophyll is a pigment found in the chloroplasts of plants and other photosynthetic organisms. It plays a crucial role in the process of photosynthesis by capturing light energy and converting it into chemical energy. The location of chlorophyll within the chloroplasts is important for its function.

The chlorophyll molecules are primarily located in the grana of the chloroplasts. The grana are stacks of thylakoid membranes, which are flattened, disc-like structures where the light-dependent reactions of photosynthesis occur. Each thylakoid membrane contains numerous chlorophyll molecules, along with other pigments and proteins involved in capturing and transferring light energy.

The chlorophyll molecules are embedded in the lipid bilayer of the thylakoid membrane. They are arranged in such a way that they form antenna complexes, where multiple chlorophyll molecules work together to capture light energy and transfer it to the reaction center. The reaction center contains a special pair of chlorophyll molecules that can undergo an electron transfer when excited by light. This initiates the flow of electrons through a series of electron carriers, ultimately leading to the production of ATP and NADPH.

While the majority of chlorophyll is located in the grana, there is also a small amount present in the stroma of the chloroplasts. The stroma is the gel-like substance that fills the space between the thylakoid membranes. It contains enzymes and other molecules involved in the light-independent reactions of photosynthesis, also known as the Calvin cycle. The chlorophyll in the stroma may play a role in capturing any light energy that passes through the grana and is not used during the light-dependent reactions.

Therefore, the correct answer is option 'A' - chlorophyll in chloroplasts is located in the grana.