According to Research Findings, What Was Found to Be an Effect

According to research findings, what was found to be an effect of college on cognitive development?

A) No difference was found in thought processes of those who attended college and those who did not attend college.
B) Mature thought was found to evolve from independent and lecture-style instructional teaching.
C) Broadened experiences and interactions with diverse faculty were found to encourage cognitive development.
D) Attending college was found to be essential to nurture Piaget's fifth stage of cognitive development.