It should be D, since the document in question has a person included themselves in the event.
The answer for this question is: Write
The main duty of a historian is to record a specific event in human history that could be passed throughout future generations.
Because of this, the most important skill to be had for historians is the ability to transform the event into a medium that could be read and understood by the generation after us.
It would let them starve so they would either surrender or all die out and destroy whats left of Germany. ☺
