The Nurse Notes That a Client's Endotracheal Tube (ET), Which

The nurse notes that a client's endotracheal tube (ET) , which was at the 21-cm mark, is now at the 24-cm mark and the client appears anxious and restless. Which of the following actions should the nurse take first?

A) Listen to the client's lungs.
B) Offer reassurance to the client.
C) Bag the client at an FIO2 of 100%.
D) Notify the client's health care provider.