A、An instrument. B、A city C、A theater. D、A concert. BWhat does the word "apple" in the phrase "the Big Apple" mean?

M: Are you ready for the trip to museums in the Big Apple? I can hardly wait.
W: The Big Apple? What are you talking about?
M: The Big Apple is the nickname for New York City.
W: Oh, tell me, where does the nickname the Big Apple come from?
M: The jazz musicians of the 1920’s are responsible for the name. When they played a concert in a city, they called that city an apple.
W: Oh, but I still can’t understand why they called it an apple instead of calling something else like a cake?
M: I am not very sure about that. New York was the biggest city in the country, and the best place for a jazz concert. So the musicians called it the Big Apple.
W: I think it’s not only a big apple for the musicians but a big apple for everyone who wants to find an opportunity in that city.
M: That’s a good idea. Well, you are going to New York with us, aren’t you?
W: Yes, I’m going to. I’m especially looking forward to seeing the Museum of Modern Arts.
M: And I heard that there’s a special show of 20th century American Painters there.
W: Amazing! New York is such a fascinating place. And it even has an interesting nickname.
M: Want to have a bite of the Big Apple, don’t you?
W: Sure.