16. Which of the following descriptions about lipopolysaccharides is NOT correct? (A) They are found in the outer membrane of Gram-negative bacteria (B) They are secreted as part of the normal physiological activity of membrane vesicle trafficking (C) They can induce defense responses in animals and plants. (D) The biological activity of lipopolysaccharides can be attributed to the chemical structure of the lipid A unit. (E) They increase the positive charge of the cell membrane and helps stabilize the overall membrane structure