Inability to absorb digested nutrients and secrete mucus might indicate a disorder in which epithelial tissue?

The answer is Simple Columnar epithelium.

Explanation:

The simple columnar epithelium may be found at the digestive tract and respiratory tract.

In the digestive system, absorption of nutrients mostly occur in the duodenum (part of the small intestines). This is covered by simple columnar epithelia with microcilia at the apical portion, also called the brush border. The brush border provides the digestive tract a broad surface area to allow optimal nutrient absorption.

In the respiratory system, a specialized type of simple columnar cells, called goblet cells, produce mucus for the mucous membrane to catch or transport foreign objects out of the system. Microcilia is also present at the apical portion of the cell and serves to trap foreign bodies that enter the respiratory tract.