Pediatrics

An infant is born at 32 weeks gestation weighing 1.4 kg. He has difficulty in breathing immediately after bih and his condition worsens thereafter. After 5 hours of delivery, the child's respiratory rate is 60/min. On examination grunting, chest retraction and marked cyanosis is present and poor air movement in chest on auscultation. Which of the following is the most probable cause for respiratory distress of this neonate?