Answer:
D ) It emphasizes the inhumane conditions the slaves
were forced to endure at the hands of European
cruelty.
What,why,how format. sorry if wrong
Professional. The tone is written in a formal and respectful way.
Since there are no options here, I believe that to make a claim effective, it must have a lot of strong evidence. It would also need to be quite logical and without errors and fallacies. It also depends on the person saying the claim - their posture and how they say it.
Sorry for that rude person but is the main about something?