Fill in the blank marked [B] using the most appropriate option.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. “turned.”
The sentence reads:
“They became afraid as the sky ______ dark.”
The most natural and grammatically correct phrasing is “as the sky turned dark”, indicating a change in state.
Grammar authorities note that “grew dark” and “turned dark” are both common linking-verb constructions describing how the sky changes from light to dark.
Option 1 (“were turning”) suggests an ongoing process that doesn't align with the sudden shift implied in the narrative.
Option 2 (“have turned”) is present perfect tense, which is inconsistent with the simple past narrative.
Option 4 (“does turn”) is present tense and inappropriate here.