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，此处考查的是主语从句，he often forgot their wedding anniversary作句子的主语，且该句成分是完整的，所以应用that引导，that没有词义，只起连接作用。故选D。