The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Which of the following statements regarding proteoglycans is true?   (A) consist of a core protein with GAG chains attached.   (B) GAG contain oxidized acid sugars   (C) negative charges cause to radiate out from the protein   (D) All of these
['(D) All of these <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) consist of a core protein with GAG chains attached. \n (B) GAG contain oxidized acid sugars \n (C) negative charges cause to radiate out from the protein \n (D) All of these <> possible answers', '  Which of the following statements regarding proteoglycans is true? <> context@']