Question

Which sentence is punctuated correctly?

The aliens suffered from exhaustion, after traveling several light years.
They needed some relaxation, when they finally landed their spaceship.
After they rested a few days, the aliens revived sufficiently to explore.
They needed all their energy, once they started hiking the rough terrain.

Answer 1

Third

Step-by-step explanation:

I would say third, it is punctuated correctly.

Answer 2

The third answer.

Step-by-step explanation:

I think the third one sounds best overall. The other ones could stand alone with out a comma.