Which sentence is punctuated correctly?

(A)
They needed some relaxation, when they finally landed their spaceship.

(B)
After they rested a few days, the aliens revived sufficiently to explore.
(C)
They needed all their energy, once they started hiking the rough terrain.

Respuesta :

B! The comma would be after explaining what happened
A.they need some relaxation when they finally landed their spaceship