This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Imaging of Lung Nodules and Masses, Subject name: Radiology
Investigation of choice for solitary pulmonary nodule - 
Select and explain. 
A. USG, B. CT Scan, C. MRI, D. X-ray
B: CT Scan
Answer: B: CT Scan 
Explanation: Ans. is 'b' i.e., CT ScanInvestigations of choice in respiratory systemDiseaseInvestigationo Intersitiai lung diseaseo BronchiectasisHRCTHRCT (1st choice)Bronchography (2nd choice)o Pulmonary embolismCT with i.v. Contrast (1st choice)V/Q scan (2nd choice)o Solitary' pulmonary noduleo Calcificationo Pulmonary malignancyo Superior sulcus or pancoast tumorCT scanCT scanCT scan (except in superior sulcus or pancoast tumor)MRI