Final answer:
The correct initial treatment for a responsive infant with a foreign body airway obstruction is to perform back slaps. Abdominal thrusts are not suitable for infants, and blind finger sweeps can worsen the situation.
Step-by-step explanation:
The initial treatment to dislodge a severe foreign body airway obstruction in a responsive infant involves back slaps. Abdominal thrusts are not recommended for infants due to the risk of injury to their delicate internal organs. In cases where back slaps do not resolve the obstruction, chest thrusts may be employed as part of the emergency procedure. Techniques such as bag-valve mask ventilation are more suitable for situations where the airway is not blocked by a foreign object but the infant is not breathing adequately. Blind finger sweeps are not recommended because they can push the obstruction further into the airway.