Dr. Lange is a developmental psychologist. He specializes 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 effects of the environment.
d. examine brain structures for signs of pathology.
I think it is a or d.
Check your book for c.
After I reread my book I agree with you that it is c.posted by Kasey