选词填空 — 英语选择题

选词填空（先判断空格所缺成分的词性，再结合时态与语义选出唯一正确选项）。句子：The archaeologists ______ that the ancient temple had been built over 2,000 years ago after examining the newly unearthed inscriptions. 备选词：A. concluded B. conclusion C. concluding D. concludes。下列哪个选项正确？A. concluded B. conclusion C. concluding D. concludes