The correct answer is C. Structural analysis
Explanation:
In language, structural analysis is a type of analysis based on the parts or structure that compose a word or a phrase. In the case of words, this type of analysis is done by breaking the word into its basic parts that usually involve separating the root word from its suffixes and prefixes, then analyzing the meaning of each part and in this way understanding the meaning of all the world. This is the process that was used in the case of the word "subterranean" because the word has been broken into its part including the root word "terra" the prefix "-sub" and the suffix "-an" and these parts that are the structure of the word have been used to understand all the word.
