If the children in the follow-up study included both 4-year-olds and 8-year-olds, researchers would likely observe:
a. more examples of parallel play among the 8-year-olds.
b. more cooperative behavior among the 4-year-olds.
c. more examples of parallel play among the 4-year-olds.
d. more harming behavior among the 4-year-olds.

C. more examples of parallel play among the 4-year-olds.

Explanation:

Parallel play usually starts after the first birthday and will be decreasing when the child starts to interact more with other kids and stop being egocentric. This kind of play consists of playing among other kids, but without interacting with each other, they observe what the other kid is doing and do the same. 4-year-olds kids are still egocentric and do not interact a lot with their mates, while 8-year-olds kids interact with each other, are not egocentric, and have a different type of play.