**Core Concept**: Vocabulary - Synonym Identification. **Analysis**: - 'Influential' means having great influence over others. - 'Dominant' (C) implies exerting authority or prevailing influence, making it the closest synonym in social contexts. - **Distractors**: - 'Effective' (A) refers to success in producing results, not influence. - 'Powerful' (B) emphasizes strength or control, not necessarily indirect influence. - 'Significant' (D) denotes importance but not the capacity to affect others. **Key Tip**: Focus on contextual usage rather than general definitions.