The Primary Lesson to Be Learned from the Example Provided

The primary lesson to be learned from the example provided in the text regarding lactose intolerance is that

A) South Asians become sick when they try to consume powdered milk.
B) Adults who are able to absorb lactose from milk effectively appear to be genetically related to human populations with a history of dairying.
C) Most human infants are able to absorb lactose.
D) Many North Americans and Europeans consume milk well into adulthood.
E) Adults without lactase can develop serious intestinal upset after consuming fresh milk.