By saying "By the end of the 20th century some experts consider these economies to be developed, rather than developing", the author suggests that South Korea is a ______.

A．The man’s wife should try to be more understanding.
B．The depression of the man’s wife may be the result of her past experiences.
C．The man’s negative attitude may be derived from his childhood.
D．It is easy for the man to help his wife out of pessimism.