A 40 year old male presented with sudden onset of severe chest pain radiating to the left upper arm. ECG was suggestive of myocardial infarction. Investigations revealed poor blood supply to the anterior 2/3rd of the interventricular septuum. Which of the following blood vessels is most likely to be blocked

The anterior 2/3rd of the interventricular septum is supplied by the left coronary aery. The right coronary aery distribution supplies Right atrium Right Ventricle ( except a small region to the right of the anterior interventricular groove ) A variable paof the diaphragmatic aspect of the left ventricle. Posteroinferior 1/3rd of the interventricular septum. Pa of the left atrium. The conduction system as far as the proximal pas of the right and left crura. The left coronary aery distribution supplies Left atrium Left ventricle A narrow strip of the right ventricle. The anterior 2/3rd of the interventricular septum Ref: Gray&;s Anatomy 41st edition Pgno: 1019