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
All of the following are features of alveolitis (interstitial lung disease), except - 
Select and explain. 
A. Exeional dyspnoea, B. Early productive cough, C. Digital clubbing, D. Coarse crepitations during inspiration
B: Early productive cough
Answer: B: Early productive cough 
Explanation: Interstitial lung disease is characterised by cough,that is typically dry & distressing,;and breathlessness,that is frequently insidious in inset ,but thereafter relentlessly progressive.Physical examination reveals the presence of inspiratory crackles and in many cases digital clubbing develops.Pulmonary function tests typically show a restrictive ventilatory defect in the presence of small lung volumes and reduced gas transfer. Reference:Davidson's Medicine-22nd edition,page no:706