33.

In proteoglycans, chondroitin sulfate is attached to the core protein by what linkage?

                                     /Man-GlcNAc-Gal-NeuNAc
a.    Protein-asn-N-GlcNAc-GlcNAc-Man
                                     \Man-GlcNAc-Gal-NeuNAc----
                          /Gal-NeuNAc
b.    Protein-ser-O-GalNAc
                          \GlcNAc-Gal-NeuNAc-----
                          /Gal-NeuNAc
c.    Protein-ser-O-GalNac
                          \Gal-NeuNAc------
d.    Protein-ser-Xyl-Gal-Gal------
e.    Protein-ser------