In Terms of Play, How Does the Typical 18-Month-Old Differ

In terms of play, how does the typical 18-month-old differ from the typical 4-year-old?

A) The typical 18-month-old spends the majority of play time engaged in cooperative play, while the typical 4-year-old spends the majority of play time in simple social play.
B) The typical 18-month-old spends the majority of play time engaged in parallel play, while the typical 4-year-old spends the majority of play time in cooperative play.
C) The typical 18-month-old spends the majority of play time engaged in simple social play, while the typical 4-year-old spends the majority of play time in parallel play.
D) The typical 18-month-old spends the majority of play time engaged in parallel play, while the typical 4-year-old spends the majority of play time in simple social play.