The following are multiple choice questions (with answers) about medical knowledge.   **Question:** A spirometry curve of a patient has been provided below. Calculate the FEV1/FVC ratio from the curve:   (A) 60-69%   (B) 70-79%   (C) 80-89%   (D) 90-99%
['(C) 80-89% <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) 60-69% \n (B) 70-79% \n (C) 80-89% \n (D) 90-99% <> possible answers', '  A spirometry curve of a patient has been provided below. Calculate the FEV1/FVC ratio from the curve: <> context@']