Introduction:

The respiratory system is one of the vital biological systems, segregated into the upper and lower respiratory system. In the upper respiratory system, nose is the outermost region comprised of the bone and cartilage. Nose is responsible for allowing air to enter the respiratory system.

Correct answer:

Stratified squamous epithelium is the one which lines the anterior 1/3^rd of the nasal cavity.

Explanation for the correct answer:

Option (a) is stratified squamous epithelium. The interior region of the nose, the nasal septum segregates the nasal cavity into two equal segments. Anteriorly, the nasal septum is made by the septal cartilage. Posteriorly, the nasal septum is made by the perpendicular plate of the ethmoid bone, as well as vomer. The stratified squamous epithelium is non-ciliated and it lines the anterior 1/3^rd of the nasal cavity while the posterior 2/3^rd of the nasal cavity is lined by the pseudostratified ciliated columnar epithelium. Hence, option (a) is the correct answer.

Explanation for the incorrect answers:

Option (b) is simple cuboidal epithelium. These comprise a single sheet of cube-shaped cells mainly found in the bronchioles. So, it is an incorrect answer.

Option (c) is pseudostratified ciliated columnar epithelium. These look stratified due to the presence of nuclei of the cells, which are situated at different levels. These have microscopic hair-like projections known as cilia, that extend from the outer region and it is found in the posterior 2/3^rd region. So, it is an incorrect answer.

Option (d) is simple squamous epithelium. This sheet of cells comprises thin and flattened cells having broad and thin nuclei. It is commonly found in the alveoli. So, it is an incorrect answer.

Hence, options (b), (c), and (d) are incorrect.