The correct answer is D) A source that's cited in another source.
Answer:
B historical facts
Explanation:
It is B because the author want to give historical facts
Efficient<span> (adj.) – Performing or functioning in the best possible manner with the least waste of time and effort. The </span>difference between effectiveness and efficiency<span> can be summed up shortly, sweetly and succinctly – Being </span>effective<span> is about doing the right things, while being </span>efficient<span> is about doing things right.
hope this could help.</span>
