Toby reads a short article and decides that its main idea is this: It is very difficult--but not impossible--to learn to ride a unicycle. Persistence is the key. What textual evidence could Toby cite to back up his claim about the article's main idea? the article’s statistics about unicycle sales last year the article’s statistics about unicycle injuries last year the article’s quote from a professional unicycle instructor the article’s quote from someone who watches unicycle races on television

C). The article's quote from a professional unicycle instructor.

Explanation:

The textual evidence that Toby can cite to support his claim regarding the central idea of the article would be the 'quotation used in the article by a professional unicycle instructor.' A textual evidences involves factual and statistical details or demonstrating examples and quotations which help justify a claim or provide support to it. Thus, the professional instructor's words would show that the claim 'persistence being the key to learn unicycle' is factual and makes an authentic and objective claim. Thus, option C is the correct answer.

c. a group of tribes that formed a confederacy

and your question what topic are you in trouble with?