A psychologist wants to conduct research on cerebral asymmetry. She wants to examine

A) brain damage.
B) intelligence.
C) intellectual disability
D) differences in right- and left-hemisphere activity.

The psychologist's research goal is to examine cerebral asymmetry, which refers to differences in right- and left-hemisphere activity. Therefore, the best choice is D, as it directly relates to the researcher's objective. Brain damage (A), intelligence (B), and intellectual disability (C) may all be related to cerebral asymmetry, but they are not the focus of the investigation.