(d) : C4 plants show kranz anatomy i.e. the mesophyll is undifferentiated and its cells occur in concentric layers around vascular bundle, which is surrounded by large sized bundle sheath cells, in a wreath like manner. In this type of plants, the initial fixation of CO2 occur in mesophyll cell. The primary acceptor (phosphoenol pyruvate) combines with CO2 to form oxaloacetic acid which later reduces to malic acid. Malic acid is then translocated to bundle sheath cell for further decarboxylation.