If you see an unfamiliar word, the meaning of the word can be discovered by thinking of 3 the part of the index that the word would be in.
Words that are of similar meaning will unusually be grouped by index in a section.
If you are unsure of what a word could mean, think about what index the word would be in and when you find out, you can then infer the meaning from the other words there.
In conclusion, option C is correct.
Find out more on indexes at https://brainly.com/question/18403284.