Dr. Lange is a developmental psychologist. He specialized in cognitive development during the period of infancy. Like most psychologists who focus on specific periods of development, his studies:

A. emphasize the chemical changes in the synaptic gap.
B. study the credibility of statistical procedures.
C. examine the relationship between biological development and the affects on the environment.
D. examine brain structures for signs of pathology.

I believe it is C

I agree.