Final answer:
The Nonfiction Signpost used in the passage is 'Extreme or absolute language,' which uses strong, emphatic language to underscore the significance of the cattlemen's struggle against livestock pests.
Step-by-step explanation:
In the context provided, the Nonfiction Signpost used in the highlighted section 'he and other cattlemen wage a continual battle against a variety of livestock pests such as coyotes, crocodiles, ticks, worms, and a host of tropical diseases' is Extreme or absolute language (Option C). This signpost is characterized by language that exaggerates or simplifies a situation, often to underscore the significance or scale of an issue. The phrase 'continual battle against a variety of livestock pests' uses strong, absolute terms that evoke the ongoing and relentless nature of the cattlemen's struggle, making it an example of extreme or absolute language.
While other nonfiction signposts like 'A number and stats' or 'Quoted words' could involve the use of specific figures or direct quotations respectively, and 'Contrast and contradictions' would highlight a juxtaposition of differing viewpoints or information, the highlighted passage does not employ these strategies. Instead, it uses emphatic language to stress the severity of the problem faced by the cattlemen, using words that leave little room for interpretation outside of an intense and ongoing effort.