which sentence is punctuated correctly?\nthe aliens suffered from exhaustion, after traveling several light…

which sentence is punctuated correctly?\nthe aliens suffered from exhaustion, after traveling several light - years.\nthey needed some relaxation, when they finally landed their spaceship.\nafter they rested a few days, the aliens revived sufficiently to explore.\nthey needed all their energy, once they started hiking the rough terrain.
Answer
Brief Explanations:
- In the first option, a comma should not be placed between "exhaustion" and "after" as the prepositional - phrase "after traveling several light - years" is a dependent clause that should come before the independent clause "The aliens suffered from exhaustion" if it starts the sentence, or not be separated by a comma when it follows.
- In the second option, a comma should not be placed between "relaxation" and "when" for the same reason as above.
- In the third option, a comma should follow "After they rested a few days" as it is a dependent clause at the start of the sentence.
- The fourth option is punctuated correctly. The independent clause "They needed all their energy" is separated from the dependent clause "once they started hiking the rough terrain" with a comma.
Answer:
They needed all their energy, once they started hiking the rough terrain.