All of the given options can help readers define words, but one option is missing: definitions. Definitions are a crucial tool for readers to understand and define words.
The correct response is:
etymological patterns.
The answer is "d. parts of speech." Parts of speech are the different categories or types of words in a language, such as nouns, verbs, adjectives, adverbs, pronouns, and so on. Understanding the parts of speech can help readers define words because it provides information about how a word functions in a sentence and its role in conveying meaning. For example, knowing that a word is a noun can help readers understand that it represents a person, place, thing, or idea. Similarly, knowing that a word is a verb can inform readers that it conveys an action or a state of being. By identifying the part of speech, readers can gain insights into the meaning and usage of words, which aids in defining them.