Bold-faced and italicized words readers by
a. showing cause and effect within a text.
b. indicating parts of speech and grammatical clues.
c. focusing attention on important words and phrases.
d. identifying main plot points and important characters.

Bold-faced and italicized words are simple text formatting that signifies emphasis on important words, concepts and details in a text. These typographic tools are keys to draw the reader’s attention towards the bold-faced or italicized words. So basically, it helps the readers by focusing attention on important words and phrases. 

The correct answer is C. focusing attention on important words and phrases.

Explanation:

I got 100% on the test.

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