According to Henrich's Mathematical Model,why Would Complex Cultural Knowledge Deteriorate,as

According to Henrich's mathematical model,why would complex cultural knowledge deteriorate,as was the case in eighteenth-century Tasmania?

A) An influx of outsiders into a population dilutes the population's cultural knowledge.
B) If malnutrition occurs,the neocortex ratio needed for the ratchet effect cannot develop.
C) Immigration creates confusion as to what qualifies as cultural knowledge.
D) Shrinkage in the population leads to a lack of skilled models for people to copy.
E) It is in the nature of cultural evolution that some cultural ideas fall out of favor in time.