John has just developed the ability to convert a declarative sentence (e.g., "i like pizza") into both a question (e.g., "do i like eating pizza? ") and an imperative (e.g., "i must eat pizza! "). this would indicate that he now is aware of

He is now aware of transformational grammar. It is a system of language breakdown that distinguishes the connection between the several elements of a sentence and between the probable sentences of a linguistic and uses methods or guidelines (which are called transformations) to signify these relationships. 

B. allowed a federal court to overrule a state court's election

decision.