input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Which of the following is used as a bio-degradable membrane in "guided tissue regeneration" process?   (A) Polylactic acid   (B) Poly tetrafluoroethylene   (C) Millipore   (D) Core membrane
output: ['(A) Polylactic acid <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Polylactic acid  (B) Poly tetrafluoroethylene  (C) Millipore  (D) Core membrane <> possible answers', '  Which of the following is used as a bio-degradable membrane in "guided tissue regeneration" process? <> context']