Question

what is the purpose of context clues?
a. to explain the authors argument
b. to provide additional facts
c. to highlight the topic sentence
d. to define unfamiliar words

Explanation:

Context - clues are used to help readers figure out the meaning of unknown words by using the surrounding text. They are not mainly for explaining an author's argument, providing additional facts, or highlighting a topic - sentence.

Answer:

d. To define unfamiliar words