Brian Has Three Children with Very Different Personality Traits

Multiple Choice

Brian has three children with very different personality traits.Even with such different personality traits,Brian sees strong maturation effects.Which of the following has Brian most likely observed?

A) All three children learned to walk at about 12 months of age.
B) Two of the three children did not crawl.
C) One of his children did not have the grasping reflex.
D) All three children preferred to sleep with the lights on.