Trachea bifurcates at-
Ans. is 'a' i.e. T4-T5 Trachea extends from the lower border of cricoid cartilage opposite C6 to the upper border of TyLength of trachea - 10-11 cm*
Trachea
T4-T5
T5-T6
T6-T7
t7-t8
T4-T5