Answer: The children's thought was stimulated, and they felt they had it in them to say much about a doll's ball, Peter, the school cat, or whatever other subject struck their fancy.
Step-by-step explanation:
Out of the excerpt provided, the chosen sentence is the one that best states the author's opinion on assisting children's development.
Considering the excerpt, the text seems to be about how to improve the education of children with some kind of impairment. The selected sentence states the importance of stimulating children´s own thoughts so they can feel they are able of much more and, therefore, aim further and get better results.
The rest of the sentences provide details on the matter, but not the main claim.