阅读以下段落，回答问题：
The widespread use of social media among teenagers has sparked intense debate about its impact on mental health. Advocates argue that platforms like Instagram and TikTok provide avenues for self-expression and community building, fostering connections that enhance emotional well-being. They highlight studies showing improved self-esteem among users who engage in positive online interactions, particularly for marginalized groups seeking peer support5. However, opponents emphasize the prevalence of cyberbullying, social comparison, and the addictive nature of these platforms. Research indicates a correlation between excessive social media use and increased rates of anxiety, depression, and sleep disturbances in adolescents5. Notably, the definition of “problematic use” remains ambiguous, complicating efforts to distinguish casual engagement from harmful behavior5. Despite these conflicting findings, policymakers struggle to balance protecting youth with preserving digital literacy and innovation.
The passage suggests that the author’s attitude toward social media’s impact on teenagers’ mental health is:
A. Optimistic
B. Pessimistic
C. Neutral
D. Ambivalent
解析：
本题考查对作者态度的推理判断，需结合对比结构和隐含立场分析。
- 作者通过 “Advocates argue” 和 “However, opponents emphasize” 客观呈现双方观点，既肯定社交媒体的积极作用（如自我表达、社区支持），又承认其负面影响（如心理健康问题）。
- 关键转折词 “However” 标志观点对比，但作者未直接表态支持任何一方，而是指出研究的矛盾性（如 “problematic use” 定义模糊）和政策困境，体现中立立场。
- 干扰项 D（矛盾）易混淆，但 “ambivalent” 强调内心矛盾，而作者仅客观描述争议，未流露情感倾向。选项 C（中立）更符合文中平衡呈现事实的基调。
