input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Most important factor in rapid progression of Bacteria resulting in pulpal necrosis is?   (A) Host resistance   (B) Virulence of bacteria   (C) Dentinal Fluid flow   (D) Pulp vitality
output: ['(D) Pulp vitality <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Host resistance  (B) Virulence of bacteria  (C) Dentinal Fluid flow  (D) Pulp vitality <> possible answers', '  Most important factor in rapid progression of Bacteria resulting in pulpal necrosis is? <> context']