Because if it was written after the time of the event, the source may be inaccurate. Also, if it was written in a different place to the event the source is taking about, that place could be particularly biased for or against that event.
Number 2 is the best answer number 3 would be wrong since the word "was "should be "were"
Answer:
I think the answer is B(domestic policy). Hope this helps!
