This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
In COPD which is true 
Select and explain. 
A. FEV1/FVC <0.7, B. FEV1/FVC (upward arrow), C. RV (downward arrow), D. TLV (downward arrow)
A: FEV1/FVC <0.7
Answer: A: FEV1/FVC <0.7 
Explanation: COPD is characterised by reduced FEV1 with a reduction in FEV1/FVC ratio less than 0.7.With worsening disease severity,lung volumes may increase,resulting in an increase in TLC,RV and FRC. Reference:Harrison's medicine-18th edition,page no:2156.