Chloroplasts are double membrane organelles with a smooth outer membrane and an inner membrane that is folded into disc-shaped sacs called the thylakoid. Thylakoids contain chlorophyll and other pigments (red, orange, yellow, brown) and are found in stacks called granum (grana, plural.)

This organelle is used to:
A. perform the process of cellular respiration.
B. expell O2.
C. create ATP.
D. covert solar energy into chemical energy.