The answer is the last one, D. All of the other transitions indicate that the writer will either go into further detail on the subject or list other reasons as to why this would be correct. However, D clearly uses a contrasting transition to introduce a new argument.
Tybalt was a capulet and Romeo and mercutio were montegues the families already had a feud if a montegue and a capulet clash and there is a murder more drama will rise but the reason mercutios death with cause problems because Romeo and Juliet were the reason it happened
The writers probably used WW2 to base the human rights on so that it would be based on major problems that needed token care of.
