—Hello! May I speak to Mary?—A.I’m Mary. B.Mary is meC.This is Mary speaking.

问题补充：

—Hello! May I speak to Mary?

—

A.I’m Mary. B.Mary is me. C.This is Mary speaking.

答案：

解析：句意：你好，我能和玛丽说话吗？我是玛丽。This is Mary speaking.是在电话用语中的习惯表达，表示正是某人通电话，故选C