LACONIC

"Laconic" is an adjective used to describe someone or something using a few words. 

"Compendious," "aphoristic," and "apothegmatic" mean stating facts or information in a concise manner. "Pleonastic," on the other hand, means the repetition of the same sense in different words, like the phrase "a true fact." 

Of all the given options, "pleonastic" would best fit as an antonym for "laconic."

Therefore, Option C is the correct answer.