Administrative assistants often answer the phone lines of their supervisors or managers. Over time, some callers' voices become familiar and easy to identify or a familiar number appears on a Caller ID screen. Other times, the voice and the caller's number are unfamiliar. What is the correct response to such calls? A. "May I inquire as to why you're calling?" B. "Who's this?" C. "That person isn't available right now, may I assist you?" D. "May I ask who's calling please?"
