What has happened to all the other characters in the scene?

Read the extract and answer the question

X: We two, my lord.
Will guard your person while you take your rest,
And watch your safety.

Y: Thank you – Wondrous heavy.

A. They have been made deaf and dumb
B. Ariel has put them all to sleep
C. They have been sent away
D. Prospero has put them to sleep

Correct Answer:

Option B – Ariel has put them all to sleep