All of the following are true about antitussives, except: (A) Dextromethorphan is a NMDA blocker which acts as central antitussive, (B) Ambroxol is a mucolytic that causes depolymerisation of mucopolysaccharides, (C) Carbocistene is a mucolytic with free sulphydryl group, (D) Baclofen is a peripheral acting antitussive
Answer is C. Carbocistene contains blocked sulphydryl group.