Right coronary artery arises from which sinus:: (A) Right aortic, (B) Left  aortic, (C) Coronary sinus, (D) Anterior aortic sinus
Answer is D. Right coronary artery
origin: Left posterior aortic sinus of aorta
Supplies :
a)  Right  atrium
 b)  right  ventricle  except  area adjoining  anterior  inter  ventricular  groove.
 c) small part of left  atrium
Left Coronary Artery
Origin:  left  posterior  aortic  sinus  of ascending aorta.
Supplies:
a) Left  atrium
b) left  ventricle except area adjoining posterior  inter  ventricular  groove 
c)  small  part  of right ventricle.