C. understand the history of the word's development over time.
Explanation:
There are various reasons why it is useful to learn a word's etymology. However, one of the most important ones is the fact that learning a word's etymology can help us learn about the word's history. Sometimes, the origin of the word can be quite different to the word's present meaning and use. This can help us understand the nuances of the word, as well as understand older texts that use the word.
