Final answer:
The closest paraphrase of the sentence 'It was a horrible time. The sky was empty. There was no light.' is option D, 'The absence of light characterized a grim period,' which encapsulates the dismal tone and the absence of light as defining of the negative experience.
Step-by-step explanation:
The best paraphrase of the underlined sentence "It was a horrible time. The sky was empty. There was no light." would capture the essence of it being a bleak period devoid of brightness or hope.
Given the options provided, 'A dreadful period ensued with a dark, vacant sky.' is somewhat similar, but it doesn't quite capture the totality of the absence of light. 'A terrible era unfolded, devoid of any brightness in the sky.' includes the absence of light but could suggest a longer span of time than is indicated by 'time.' 'The sky remained dark and empty, making it a dreadful time.' restates the elements of the original sentence but slightly alters the construction with 'making it.' 'The absence of light characterized a grim period.' aptly conveys all aspects of the original sentiment, but this option rearranges the sentence structure and emphasizes the lack of light as a defining characteristic of the dismal time. Based on the provided examples, the closest paraphrase is option D.