Salutations!
<span>A change from talking to singing best illustrates a change in _________.
</span><span>A change from talking to singing best illustrates a change in action. An instant change in what we are doing is called action. An action means an act, or a thing done. Talking to singing is clearly shown a change in the action.
Thus, your answer is option D.
Hope I helped :D</span>
This look hard, good luck on it.