Which of the following tendencies is a gender difference in play for children?

A) Boys play violent video games and girls play with Barbie dolls.
B) Children avoid "opposite-gender" toys during preschool and elementary years.
C) Children express strong preferences for gender-typed toys.
D) All of these answers are correct.

All the options listed reflect observed gender differences in play for children. Boys often gravitate towards more aggressive or action-oriented games, including violent video games, while girls are more likely to play with dolls, such as Barbies. Both boys and girls tend to avoid toys that are stereotypically associated with the opposite gender, especially during the preschool and elementary years. Additionally, children express strong preferences for toys that are culturally and socially identified with their own gender, a pattern that is consistently observed across various cultures and studies.