The underlined word “testament” in Paragraph 4 is closest in meaning to “______”.

参考解析：

词义猜测题。根据第四段第四句“‘Normal People’ strengthened Sally Rooney’s reputation as the voice of her generation and one of the most exciting novelists around today.”《普通人》巩固了Sally Rooney作为她那一代人的代言人和当今最令人激动的小说家之一的声誉。下文“Its success is a testament to the health of literary fiction and indicates that there is still significant appetite for excellent storytelling.”它的成功证明了文学小说的健康发展，并表明人们仍然对优秀的故事情节有着巨大的兴趣。根据上面两句的句意可推测testament的意思是“证明”。A项debate意为“辩论”；B项exam意为“考试”；D项state意为“状态”，均不符合句意。故选C。