The following are multiple choice questions (with answers) about medical knowledge.   **Question:** In CPITN index zero score means:   (A) Gingival bleeding   (B) Grade 1 mobility of teeth   (C) Healthy tooth   (D) Spontaneous bleeding
['(C) Healthy tooth <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Gingival bleeding \n (B) Grade 1 mobility of teeth \n (C) Healthy tooth \n (D) Spontaneous bleeding <> possible answers', '  In CPITN index zero score means: <> context@']