A five day old,full term male infant was severely cyanotic at birth.Prostaglandin E was administered initialy and later ballooned atrial septosomy was done which showed improvement in oxygenation.The most likely diagnosis of this infant is:

• A. Transposition of great vessels
• B. Tetralogy of Fallot
• C. Tricuspid Atresia
• D. Truncus Arteriosus