Read the following statements  
A) Ground tissue of the ground tissue system consists of simple tissues such as parenchyma, collenchyma and sclerenchyma
B) The proton gradient is broken down due to movement of protons across the membrane from the stroma, whose moving force is ultimately used to synthesize ATP during chemiosmosis in the chloroplast. 
C) Respiratory organs, namely stomata and lenticels, help in aerobic respiration in plants.
D) In dicots and gymnosperms, apical meristems, namely vascular cambium and cork cambium help in secondary growth. 
The correct statements are