**Core Concept**: Synonym identification (Vocabulary). **Analysis**: 'Tepid' means moderately warm, often implying a lack of enthusiasm. 'Lukewarm' (C) directly matches this meaning. - **A. Cold** and **B. Hot** are antonyms or extremes. - **D. Moderate** refers to degree, not temperature. **Key Point**: Focus on contextual temperature-related synonyms. **Common Mistake**: Confusing 'moderate' (general degree) with temperature-specific terms.