Look carefully at the model. plants take in and release carbon dioxide. plants require carbon dioxide for the process of a) condensation. b) photosynthesis. c) respiration. d) transpiration.

B) Photosynthesis  

Plants use the energy from the sun to convert it into carbon dioxide and water  and oxygen. The plants also use the sugar for food then they release oxygen into the air

The answers are in bold and in order...

Bacillus A (rod-shaped)

Spirillum B (spiral-shaped)

Coccus C (spherical)

I know that these are correct, and I hope this helps anyone in the future. Good luck!