Question

what caused humans to be able to drink and ingest milk even after infancy unlike other animals? chemicals in the milk added to humans dna and adapted it a beneficial mutation of the lactose gene we were always able to drink milk

Explanation:

Lactose intolerance is common in many animals after infancy. In humans, a beneficial mutation in the lactose gene (specifically, the LCT gene) allows for the production of lactase (the enzyme that digests lactose in milk) beyond infancy. This mutation became prevalent in human populations that practiced dairy farming due to the selective advantage (nutritional benefits from milk as a food source). Milk - derived chemicals do not directly add to human DNA in the way described in the first option. And humans were not always able to drink milk; it was a result of genetic changes over time.

Answer:

a beneficial mutation of the lactose gene