What is the primary cause of Lactose intolerance in individuals with a rare genetic disorder?

A Deficiency of Lactase enzyme ✓
B Overproduction of Lactose
C Impaired glucose absorption
D Increased gut motility

Explanation

Lactose intolerance is caused by the deficiency of lactase enzyme, which breaks down lactose into glucose and galactose. In individuals with a rare genetic disorder, this enzyme is not produced or is produced in insufficient quantities.

Source

Guyton and Hall Textbook of Medical Physiology
Metabolic and Nutritional Disorders Gastrointestinal Disorders Lactose Intolerance Medium MEDICAL Confidence: high