单选题 ______ he often forgot their Wedding anniversary greatly annoyed his wife.
【正确答案】 D
【答案解析】[解析] 分析句子结构可知，句子缺少主语，所以空格处应为引导主语从句的连接词。又因为句子he often forgot their wedding anniversary的成分是完整的，所以要用没有词义而只起连接作用的that引导。故选D。