C, i think is the answer.
A dictionary is a source you can use to find definitions of words.
A thesaurus is a source you can use to find synonyms/antonyms for certain words.
These two combined can help you choose words that are not commonly used and it can improve your vocabulary range. I personally use a thesaurus way more than a dictionary to find synonyms for common words such as “good” or “smart”
Would the relationship be the cereal goes in the bowl? Because then I'd do milk: carton.