I think it is line 4 (since it repeats granite twice) Hope this helps!
D) Their greed over the gold leads to their actual deaths
1. Authority
Note the mention of "Nobel prize-winning scientist", which is generally the most prestigious scientists out there. What they say usually have authority and is believed by the ordinary people.
2. Emotion
First of all, how does the author know that the group is made up of "bigots". This is playing on the person's emotions, and trying to make them angry at their mistake, as well as give them a different group that they should look into.
3. Appeal to Logic
Note the usage of "make sense", as well as the building up of argument from the logical conclusion that "Diversity makes sense.. (via these reasons)".
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I'm pretty sure it is a metaphor
