I believe the answer is: B. the shooting of an unarmed rider.
In the speech, there is a dark connotation that made by the speaker when he mentioned the shooting of unarmed riders who are not willing to conform to their orders. Especially to the lower ranks who are bound by the orders from higher officers.
Answer:
2. Date
Explanation:
Some sources will state historic events, however if they were written a long time AFTER the events happen it is not credible because the person who wrote the source was not present at the time of the event.