1. Which description below about C3 and C4 plants are INCORRECT?
(A) Among all plant families, the grass family has the highest number of species using the C4 photosynthetic pathway.
(B) Photosynthesis in C3 plants lead to lower fractionation compared to that in C4 plants.
(C) C4 photosynthesis is evolutionarily younger than C3 photosynthesis.
(D) C4 plants are in general more efficient in water usage than C3 plants.