The phrase "hang-dog fury" comes form the text "The Rainbow" by D. H. Lawrence. The word "fury" indicates that this phrase is not positive in any way, so any option that leans toward positive or even neutral as a definition is incorrect. Eliminate options A and C. The sentence after the one in which "hang-dog fury" can be found begins "And the feud continued". This shows that there is obvious hatred and animosity between the groups since a feud is a long-standing fight. Also, since fury and furious are from the same root, this would be a good choice.
Research cannot be opinionated because it wouldn't be true. You may think something may be something else when doing research (a hypothesis) but it has to be factual. But in short it is false.
