Statement A: Rubisco of bundle sheath cells of C₄ plants shows more carboxylase activity than the mesophyll cells of C₃ plants.

Statement B: High CO₂ concentration is maintained in bundle sheath cells of C₄ plants than in mesophyll cells of the same plant.

The CO₂ involved in carboxylation of PEP in mesophyll cells of C₄ plants is pumped into bundle sheath cells to maintain high CO₂ concentration to avoid or decrease the oxygenase activity of Rubisco. In C₃ plants, the CO₂ concentration of its green cells is far lower. Hence these plants show relatively more photorespiratory loss of carbon than C₄ plants.