Answer: Last option (sleep)
Step-by-step explanation:
Definition of slumber
(Entry 1 of 2) intransitive verb. 1a : to sleep, especially lightly; doze; drowse. to be in a state of inactivity, negligence, quiescence, or calm: Vesuvius is slumbering.
examples;
He had fallen into exhausted slumber.
He roused Charles from his slumbers.
The older three girls are still slumbering peacefully.