Three-Year-Old Tina Enjoys Having Pretend-Play Time with Her Older Sister

Three-year-old Tina enjoys having pretend-play time with her older sister. 3-year-old Marcelle, on the other hand, does not have a sibling close in age and often plays by herself. Compared to Marcelle, Tina is more likely to

A) be less comfortable playing by herself.
B) be at higher risk for externalizing and internalizing problems.
C) show anxiety when left alone in a room.
D) develop an earlier understanding of false-belief.
E) engage in more aggressive behaviors with peers.