in order to study the schools of children from poor families, Jonathan Kozol moved to several different U.S. cities and taught in their poorest schools. After doing this for a few years, he wrote a book about his findings. Kozol’s work is an example of a/an ___ study.

Are these your choices?

A. cross-sequential

B. ethnographic

C. migrogenetic

D. longitudinal

I'll be glad to check your answer.