Mayan refugees to the USA today and European immigrants in the 1800s and early 1900s are taller than those who stayed home. Why?

A) in the USA there was/is more abundant food and better drinking water
B) they interbred with those already here in the USA
C) this is a trick question: they are not taller
D) with less adequate food, their bodies prioritized organ development over height
E) more exercise