Which of the following statements True?
a. Gram-positive bacteria have a single cell wall formed from peptidoglycan.
b. Gram-positive bacteria have an outer membrane.
c. The cell wall of Gram-negative bacteria is thick, and the cell wall of Grampositive bacteria is thin.
d. Gram-negative bacteria have a cell wall made of peptidoglycan, while Grampositive bacteria have a cell wall made of phospholipids