Rachel Is a 6-Month-Old Who Has Recently Learned to Sit

Rachel is a 6-month-old who has recently learned to sit up on her own. Her mother places two toys in front of her: a soft, yellow, stuffed animal within her reach and a colorful rattle slightly out of her reach. Seeing both toys, Rachel chooses the one she finds more appealing to play with. Over time, choices such as these may:

A) influence her development of crawling.
B) influence the development of her understanding of cause and effect.
C) be active contributions to her development.
D) influence the development of her personality.
E) All of the answers are correct.