Which of the following is not a subcategory of linguistics?

The correct answer is C, as psychoanalysis is a branch of psychology focused on the study of the unconscious mind, mental processes, and therapeutic techniques, rather than a subcategory of linguistics. Linguistics itself encompasses various subfields that focus on different aspects of language.

Phonology relates to the sounds of speech and how they are organized in particular languages. Morphology deals with the structure of words and how they are formed, including the study of prefixes, suffixes, and root words. Syntax focuses on the rules and patterns that govern sentence structure and how words combine to form grammatically correct sentences. Each of these areas is essential for understanding the complexities of language, while psychoanalysis does not pertain to the study of language structure or use.