Final answer:
After a tonsillectomy, placing the child in a side-lying (option b) position is recommended to facilitate drainage and prevent aspiration of blood or secretions.
Step-by-step explanation:
The side-lying position is typically recommended for a child returning from the operating room following a tonsillectomy. This position helps to facilitate drainage and can prevent the child from aspirating any blood or secretions that may accumulate in the mouth or throat post-operatively, which is crucial for patient safety. Other positions like supine, Trendelenburg, or High Fowler's are generally not preferred in the immediate post-operative period for a patient recovering from a tonsillectomy.