freezing and thawing growth and reproduction evaporation and precipitation photosynthesis and respiration
I gave my students this multiple choice question: Which are two parts of the carbon cycle?

Only one answer is correct among these 4 choices:
- freezing and thawing
- growth and reproduction
- evaporation and precipitation
- photosynthesis and respiration

Could you tell me which one is correct?

photosynthesis and respiration