Which relative pronoun correctly completes the sentence: 'Patients ______ feel their rights are violated may file a complaint.'
答案解析
核心考点：定语从句关系代词的用法。解题思路：先行词为表示人的patients，且从句中缺少主语，应使用关系代词who。选项分析：D正确，who指代人并在从句中作主语；A/B/C均用于非人或错误语法功能。易错点：混淆which（指物）和who（指人）。
正确答案：D