Tracy and Shahid Are Both 3 Months Old

Multiple Choice

Tracy and Shahid are both 3 months old. Tracy is highly active, easily irritated, and cries easily. Shahid is quiet, adapts easily to change, and seems fearless. These differences illustrate ________

A) the impact of shared environmental influences.
B) how physical handicaps can have a genetic origin.
C) differences in temperament.
D) the fact that personality is more influenced by the environment than by genetics.