input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Radiograph of a periodontal ligament of a tooth which has lost its antagonist shows:   (A) Widening of the PDL space   (B) Narrowing of PDL space   (C) Increased density   (D) Sclerotic change
output: ['(B) Narrowing of PDL space <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Widening of the PDL space  (B) Narrowing of PDL space  (C) Increased density  (D) Sclerotic change <> possible answers', '  Radiograph of a periodontal ligament of a tooth which has lost its antagonist shows: <> context']