<prompt> Which of the following structuers is inferior to spheno petrosal Synchondrosis-Abducens nerveOsseous pa of auditory tubeCailaginus pa of auditory tubePetro squamous sinus  <response>: Sphenopetrosal synchondrosis is cailagenous union bw lateral half margin of great wing of sphenoid petrous bone. On the under surface of sphenopetrosal synchondrosis, is a furrow, the sulcus of auditory tube for lodgement of cailagenous pa of auditory tubeQ 