Somebody phoned me from your office while I was out, ____ ?A. didn't theyB. did theyC. didn't itD. was it

步骤 1：理解句子结构
句子的主句是 "Somebody phoned me from your office"，而 "while I was out" 是一个时间状语从句。整个句子的主语是 "Somebody"，谓语是 "phoned"，宾语是 "me"，地点状语是 "from your office"。
步骤 2：确定反意疑问句的结构
反意疑问句的结构是 "陈述句 + 简短疑问句"。陈述句是肯定形式，简短疑问句则是否定形式，反之亦然。陈述句的主语是 "Somebody"，谓语是 "phoned"，因此简短疑问句的主语应该是 "they"，谓语应该是 "didn't"。
步骤 3：选择正确的选项
根据上述分析，反意疑问句的正确形式应该是 "didn't they"，因此选项 A 是正确的。