input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Pickling:   (A) Is accomplished by soaking the casting in baking soda   (B) Causes porosity in gold   (C) Removes surface oxides from gold castings   (D) Remove investment from gold casting
output: ['(C) Removes surface oxides from gold castings <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Is accomplished by soaking the casting in baking soda  (B) Causes porosity in gold  (C) Removes surface oxides from gold castings  (D) Remove investment from gold casting <> possible answers', '  Pickling: <> context']