tom said he___at that time A.is cooking B.cooked C.was cooking D.cooks

tom said he_C__at that time A.is cooking B.cooked C.was cooking D.cooks
首先是said过去时,后面排除AD
另外这里有at that time表示在那个时候,所以是在哪个时候他正在做饭,选择C