Question: The medium that is used to detect the production of acetoin (butylene glycol) from pyruvic acid in the fermentation of glucose is called: 
 Options:  <1> Kligler. <2> Methyl red. <3> Voges Proskauer. <4> ONPG (ortho-nitrophenyl-galactopyranoside) <5> Beta-glucuronidase.
3