Final answer:
General anesthesia (option A) is typically used for tympanostomy tube replacement in children to safely manage breathing and airway control during surgery.
Step-by-step explanation:
The type of anesthesia typically used for the replacement of a tympanostomy tube in a normally healthy 7-year-old is general anesthesia. This is because general anesthesia affects the muscles necessary for breathing and moving the tongue, which can relax and potentially block the airway during a procedure. To manage this risk and ensure the patient's safety, an endotracheal tube is placed into the trachea, which allows the doctors to maintain an open airway to the lungs and seal the airway off from the oropharynx. After the surgery, the anesthesiologist will gradually change the gas mixture that keeps the patient unconscious, allowing for the patient to wake up and for the breathing muscles to regain control over respiration, although it can take about 30 minutes for full recovery.