Lt border of the heart in CXR is formed by – a) Pulmonary arteryb) Pulmonary  veinc) Abdominal aortad) Arch of aortae) Rt ventricles: (A) b, (B) c, (C) ad, (D) ab
Answer is C. The left margin of heart is formed by aortic knuckle (prominence due to aortic arch), pulmonary trunk, left auricle, and left ventricle.