Consider the following statements : 

a) The middle lamella is a layer mainly of calciumpectate which holds or glues the different  neighbouring cells together

 b) A non-living rigid structure called the cell wall forms an outer covering for the plasma membrane of fungi and plants

c) Peripheral proteins lie on the surface of cell membrane while the integral proteins are partially or totally buried in the membrane

d) Biochemical investigation clearly revealed that the cell membranes also possess protein and carbohydrate

 How many of the above statements are incorrect ?