Have you ever wondered who writes the Nancy Drew mysteries? Many fans of the series may be surprised to learn that there is no Carolyn Keene. Carolyn Keene is a pseudonym created by the series' father, Ed Stratemeyer, and it is shared by an unknown number of ghost writers. The first "Keene" was Mildred Wirt Benson, who fleshed out the outline Stratemeyer had developed for the titian-haired detective. Writing one book about every six weeks, Benson is credited with a majority of the first 30 Nancy Drew mysteries.

What is the definition of pseudonym as it is used in this paragraph?
A.
a made-up name
B.
a female author
C.
a character in a book
D.
a mystery novel