before, until

[joham]

Nearly a month had gone by _____ they went out of the forest.
A. until B. while C. before D. after
(The given answer is C.)
I'd like to know if A is also fine. And why?

Thank you very much.

[henz988]

Nearly a month had gone by _____ they went out of the forest.
A. until B. while C. before D. after
(The given answer is C.)
I'd like to know if A is also fine. And why?

"they went out of the forest" is just a point of time; until doesn't work here in that it refers to a period of time.

Let's see how natives will explain the question.

[puzzle]

Any comments?

[puzzle]

Any comments? Please.

[shalstudent]

The choices that match here are:

1) Nearly a month had gone by before they went out of the forest- meaning they did not get out of the forest for almost a month.

2) Nearly a month had gone by after they went out of the forest- meaning they went out of the forest almost a month ago.

I dont' think that "until" and "while will be suitable here.

[henz988]

Nearly a month had gone by _____ they went out of the forest.
A. until B. while C. before D. after
(The given answer is C.)
I'd like to know if A is also fine. And why?

"they went out of the forest" is just a point of time; until doesn't work here in that it refers to a period of time.
-----------
“Nearly a month had gone by” is just a description of a fact, and the fact itself doesn’t last up to the point of time (please don’t be confused by a month) when they “went out of the forest.” In other words, “Nearly a month had gone by” means a terminative action, not a period of time.
I hope I have made myself understood.

[apex2000]

The wording of the latter part is not best practice:
....they went -
....they left the forest. cf Fowler

Although went (used to be past tense of wend) is now usually the past tense of go, go is motion and does not fit the sentence. Left as past tense of leave is not only better English and better spoken English it is more correct.