Which of the following ventilator settings or respiratory measurements would be LEAST acceptable for a newborn with congenital diaphragmatic hernia (CDH)? (A) 100% FiO₂ (B) PEEP of 20 cm H₂O (C) Inhaled nitric oxide (NO) (D) PaCO₂ of 55 mmHg (E) PaO₂ of 65 mmHg