Here's a problem to solve: Which statement best describes the roles of photosynthesis and respiration in the carbon cycle?

Among the 4 following options, which is the correct answer?

- A: Respiration and photosynthesis both add carbon to the atmosphere.
 
- B: Respiration and photosynthesis both remove carbon from the atmosphere.
 
- C: Respiration adds carbon to the atmosphere, while photosynthesis removes carbon from the atmosphere.
 
- D: Photosynthesis adds carbon to the atmosphere, while respiration removes carbon from the atmosphere.
 