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
A 5-year-old woman presents with dry cough and progressive breathlessness of two years duration. Examination reveals clubbing, cyanosis and bibasilar crepts. What is the probable diagnosis - 
Select and explain. 
A. Bronchiectasis, B. Lung abscess, C. Interstitial lung disease, D. Pulmonary tuberculosis
C: Interstitial lung disease
Answer: C: Interstitial lung disease 
Explanation: Interstitial lung diseases like pulmonary fibrosis are characterised by the the presence of exeional dyspnea,a nonproductive cough,and bi-basilar inspiratory crackles with or without digital clubbing.Cyanosis can be present due to respiratory compromise. Ref:Harrison's med:18th edition,page no:2165.