A young patient is diagnosed with the genetic disorder lactose intolerance, which results in the inability to digest milk products due to a missing enzyme called lactase. What is most likely the cause of lactose intolerance in this patient?

Question 1 options:

a. The patient is allergic to milk.


b. The patient stopped consuming milk products.


c. A disease destroyed the lining of the patient’s small intestine.


d. A mutation occurred in the gene that is responsible for producing lactase.