Which of the Following Observations Would Provide the Strongest Support

Which of the following observations would provide the strongest support that the process of language is biologically based?

A) Children from all over the world acquire language milestones at about the same age and in the same approximate order.
B) Children benefit when their parents and teachers actively engage them in conversation and ask many questions.
C) Children can be trained to speak words even before they are able to understand the meaning of those words.
D) Children tend to understand nouns and verbs before they are able to understand adjectives and adverbs.