text:  #IDSky #MedSky #PharmSky @idsainfo.bsky.social @cidjournal.bsky.social @ofidjournal.bsky.social @sidpharm.bsky.social
  
  Which component of lipopolysaccharide (LPS) is useful for distinguishing gram-negative bacteria?
  A. Core polysaccharide 
  B. Lipid A
  C. O polysaccharide 
  D. Periplasmic antigen