2 months old child, born prematurely is brought with respiratory distress. Cardiac examination reveled increased pulse pressure and a pansystolic murmur best heard in 2nd left intercostal space. he most probable diagnosis would be -

• A. Atrial septal defect
• B. Ventricular septal defect
• C. Patent ductus arteriosus
• D. Tetralogy of Fallot's