In Which of the Following Circumstances Should a Helmet Be

In which of the following circumstances should a helmet be removed?

A) If you suspect a skull fracture and need to palpate the head
B) If you want to place a nasal cannula on the patient but cannot because his ears are covered by the helmet
C) If the helmet interferes with airway management
D) If the helmet fits so snugly that you cannot inspect the ears for the presence of blood or fluid