The bifurcation of trachea occurs most commonly at
High-Yield Explanation
"The level of bifurcation of the trachea varies from the lower third of the fouh to the middle of the seventh thoracic veebrae. The average position is at the level of the lower third of the fifth thoracic veebra.Ref: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition, pg no. 319