Which of the following statements is (are) TRUE for carbon, nitrogen and phosphorus cycles? You can select up to 2 statements a. CO₂ is produced via respiration as a by-product al b. The carbon, nitrogen and phosphorus cycles all have a gaseous phase. c. Nitrogen can be cycled without the involvement of bacteria. d. Phosphate can be assimilated by plants e. Nitrogen in its gas form (N₂) can be assimilated by plants.