The diagram shows the structure of a chloroplast. A chloroplast is a rounded chamber surrounded by a membrane. Inside are many small rounded chambers called thylakoids, which are arranged in stacks called grana. The space outside the thylakoids is the stroma.

Sandra wants to modify the diagram to include chlorophyll. Which would be the most useful strategy?

A. Add representations of chlorophyll molecules inside the stroma.
B. Add representations of chlorophyll molecules on the outer membrane.
C. Group two or more grana together, and label them as chlorophyll.
D. Add an enlarged illustration of a thylakoid, and represent chlorophyll molecules in the thylakoid membrane.