Final answer:
If the mother says, "I'll let him decide when to return to his play activities," further teaching is necessary.
Step-by-step explanation:
If the mother of the child says, "I'll let him decide when to return to his play activities," it indicates that further teaching is necessary. After a child undergoes an orchiopexy to correct cryptorchidism, the child needs to take adequate rest and avoid strenuous activities for a certain period as advised by the healthcare provider. The decision about when to return to play activities should be made based on medical guidance, not the child's preference.