Killian dehiscence is in -

Ans. is 'b' i.e., Inferior constrictor o Inferior constrictor has two partsUpper Propulsive Part - Thyropharyngeus with oblique fibers.Lower Sphineteric part - Cricopharyngeus with transverse fibers.o Between these two parts exists a potential gap called "Killian's dehiscence".o it is also called "Gateway of tears" as perforation can occur at this site during esophagoscopy.o This is also the site for herniation of pharyngeal mucosa in cases of pharyngeal pouch (pharyngeal diverticulum)