Although the chairman didn't mention any name, we all knew he wa

Although the chairman didn't mention any name, we all knew he was （） his secretary.

referring to

saying

touching on

suggesting

句意：尽管董事长没有提到任何人的名字，我们都知道他指的是他的秘书。refer to意为“提及到，说到，指的是”，符合题意。