The character Mavis is introduced to the reader: 3. through her dialogue that indicates that she is very efficient.
Characterization is the attribute of a given person in a text. In the text, Mavis is described as an efficient employee who attends to the customer on time, and in a very courteous and polite manner.
She is portrayed as dutiful and this is seen in the things she tells the speaker. So, option 3 is correct.
Learn more about characterization here:
https://brainly.com/question/1393329