Which line from the novel is an example of dialect?
a.
"you don't know anything."
b.
"you are going to your uncle."
c.
"an' tha's browt th' young 'un with thee."
d.
"i suppose i may as well tell you something about where you are going to."

C. would be an example of dialect.

Dialect is the sound or form of a language in a specific region.  Choices A, B, and D just give words in a sentence the way they are supposed to be spelled; you can't tell how they were pronounced.  Choice C changes the spelling of the words and adds apostrophes to show some of the different pronunciations in the sentence. For example, Choice C doesn't say "the", it says "th'". It gives you a clue to how it would be pronounced in this dialect.