Final answer:
The mental dictionary referred to in the question is called a lexicon (option A), which is the vocabulary of a language and essential for communication and understanding. It differs from a thesaurus, glossary, or concordance, and is used alongside grammar to comprehend and produce language.
Step-by-step explanation:
The mental dictionary in every person's phonological processing system is known as a lexicon. The lexicon of a language encompasses the entire vocabulary of that language, providing words that can be utilized for communication.
Unlike a thesaurus, which lists synonyms, or a glossary, which defines terms specific to a particular field, the lexicon is a more general concept that applies to the entirety of a language's vocabulary, including spelling, pronunciation, and meaning. Similarly, a concordance typically refers to an alphabetical list of the principal words used in a book or body of work, with their immediate contexts.
When it comes to understanding and processing language, concepts and their categories are crucial for organizing the wealth of information we encounter, and they make this information accessible and manageable within our cognitive structures.
When discussing language acquisition and usage later, it becomes clear that grammar also plays a significant role alongside the lexicon, directing how words are put together to convey meaning. The interaction between grammar and the lexicon allows individuals to comprehend and produce language effectively. As such, the lexicon is a critical component of language and cognition, highlighting its integral place in communication and understanding.