Answer: The sentence that uses the bolded word correctly is the first one: "The caustic, bitter remarks about the company CEO in the newspaper were obviously slanderous".
Step-by-step explanation: The word "slanderous" is an adjective used to describe something as false and malicious. In this sentence, "slanderous" is characterizing "remarks", a noun that is also being premodified by "caustic" and "bitter". Therefore, the use of "slanderous" is coherent since this word is related to the context of the sentence. In contrast, "clamorous" has not been correctly used because the noun that is modifying is also being premodified by "peaceful", which is opposite in meaning to "clamorous". Moreover, "beseeched" and "recompense" do not fit in their sentences either.