Early childhood education professionals contribute by
a. developing policies that advocate for certain groups of children.
b. participating in strikes.
c. defining the roles and responsibilities of parents.
d. conducting their own research collaborating with parents.

D. conducting their own research collaborating with parents.

Explanation:

Early childhood education professionals are very important for the creation of policies that help both parents and children. These professionals contribute to the field of childhood education by conducting research in collaboration with parents. This research not only allows us to learn more about children's education and development, but it also helps children and parents have a smoother and more enriching development process.

1 - shakespeare

2 - stephen king

3 - stephenie meyer

4 - seiichi morimura

5 - sabrina elkins

6 - sally cheney

7 - samantha hunter

8 - shelley bates

9 - sue civil-brown

10 - sylvie kurtz