Ans. is 'a' i.e., 2 D- Echocardiography o Investigation of choice for valvular heart disease - 2D-echocardiography.o 2 D-echo is the investigation of choice for pericardial effusion.Investigationso Investiation of choice to identify individual cardiac chamber enlargement - 2D echocardiography.o Investigation of choice for pericardial effusion -2D-echocardiography.o Investigation of choice for valvular heart disease - 2D-echocardiography.o Investigation of choice for cardiomyopathy - 2D-echocardiograpby.o Investigation of choice for cardiac temponade - 2D-echocardiography.o Investigation of choice for aortic dissection in stable patient - MRI.o Investigation of choice for aortic dissection in unstable patient TEE.o Investigation of choice for ventricular function and size - Echocardiographyo Investigation of choice for congenital heart disease - Echocardiography,o Investigation of choice for pericardial defect - MRI.o Investigation of choice for radiotherapy/chemotherapy induced myocardial damage Endomyocardial biopsyo Investigation of choice for myocardial perfusion and viability (reversible ischemial -- PET > Nuclear cardiac imaging (thallium scan or Technetium scan).o Investigation of choice for asymptomatic carotid bruit - Duplex ultrasound (B-mode scan and doppler ultrasound velocitometry).o Most sensitive investigation for air embolism - Trans-esophageal echocardiography.o Second most sensitive investigation for air embolism - Precordial Doppler.o Best x-ray view for right atrial enlargement - Left anterior oblique view.o Best x-ray view for left atrial enlargement - Right anterior oblique view with barium swallow.