9. The major difference between a typical C4 plant and a C3 plant, is that
(A) The C3 plant has a smaller opening of stomata, so that less CO2 can enterthe plant.
(B) The C4 plant only uses PEP carboxylase to catalyze all carbon fixation.
(C) Rubisco in C4 plant has a high binding affinity to CO2 than that in the C3
(D) The carbon fixation rate in C4 plants is always higher than C3 undervarious growth temperatures.
(E) The C4 plant only carries out the Calvin cycle only in the chloroplasts ofbundle-sheath cells.