Concept:Mellifluous means sweet or pleasant to hear. Its synonym is a word with a similar meaning.Explanation:Mellifluous refers to a sound that is smooth and sweet. Dulcet also means melodious or soothing to the ear. Thus, dulcet is the correct synonym.Other options: Bland means dull or tasteless. Conspire means to plot secretly. Obnoxious means extremely unpleasant. None of these match.Answer:Option C. Dulcet