A charge nurse in the emergency department is reviewing the data of four young children who are receiving treatment. Which of the following should alert the charge nurse to the possibility of child maltreatment?

A 21-month-old toddler who has digoxin poisoning after opening and ingesting a relative's pills

A 12-month-old infant who is not wearing a coat in their car seat in the winter

A 15-month-old toddler who had a submersion injury after falling face-first into a toilet

A 3-month-old infant who has a complex skull fracture from rolling off the changing table