Which of the following types of epithelium consists of a single layer of cells of varying heights?

The type of epithelium that consists of a single layer of cells of varying heights is known as pseudostratified columnar epithelium. Despite appearing to have multiple layers due to the varying heights of the cells, this type of epithelium is actually a single layer. The nuclei of these cells are at different levels, which gives the illusion of being stratified. However, each cell is attached to the basement membrane, confirming it as a single layer. This type of epithelium is commonly found lining the trachea and upper respiratory tract.