Which of the following statements is incorrect?
1. The tracheal mucosa consists of pseudostratified ciliated columnar epithelium.
2 .The trachealis muscle and elastic connective tissue allow for changes in the diameter of the trachea.
3. The trachea is located posterior to the esophagus and extends from the larynx to the superior border of the fifth thoracic vertebra.
4. The trachea has incomplete hyaline cartilage rings.

The trachea is located posterior to the esophagus and extends from the larynx to the superior border of the fifth thoracic vertebra.

Explanation:

This is a wrong  statement. Anatomically ,this organ of upper respiratory system is located anterior to the oesophagus.Thus it  is the oesophagus that is located posterior to the trachea.

It passes through the posterior mediastanium to branch into the left and right main bronchi.

it  bends towards it ends to the right,which results in the crossing of the left main bronchus anteriorly to the oesophagus.

It is lined by mucus gland produced by pseudo stratified columnar cells and some ciliated and non ciliated cells.

The mucus helps in warming up inhaled air and filtration of the air of dust particles.

i think that d. wind is the answer.   i missed the question when i answered a. currents.