Double atrial shadow in mitral stenosis due to -

Ans. is 'a' i.e., Left Atrial enlargement Sings of left atrial enlargementStraightening of left heart border (due to enlargement of left atrial appendage).Elevation of left main bronchus with widening (Splaying) of carina.Double density (atrial) sign.Posterior displacement of esophagus on barium swallow.Prominent posterosuperior part of cardiac shadow.