My father' s response to the bank building at 43rd Street and Fifth Avenue in New York city was immediate and definite: "You won' t catch me putting my money in there!" he declared, "Not in that glass box. " Of course, my father is a gentleman of the old school, a member of the generation to whom a good deal of modern architecture is upsetting, but I believe that his negative response was not so much to the architecture as to a violation of his concept of the nature of money. In his generation money was thought of as a real commodity  that could be carried, or stolen. Therefore, to attract the custom of a sensible man, a bank had to have heavy walls, barred windows, and bronze doors, to make sure of the fact, however, untrue, that money would be safe inside. If a building' s design made it appear strong, the institution was necessarily reliable, and the meaning of the heavy wall as an architecture symbol showed the general attitude toward money. But the attitude toward money has, of course, changed. Except pocket money, cash of any kind is now rarely used; money as a tangible commodity has largely been replaced by credit. The banker no longer offers us a safe: he offers us a service in which the most valuable factor is the creativity for the invention of large numbers. It is in no way surprising, in view of this change in attitude, that we are witnessing the disappearance of the heavy-walled bank. Just as the older bank emphasized its strength, this bank by its architecture is proud of imaginative powers. The main idea of this passage is that   _  .
money is not as valuable as it was in the past changes have taken place in both the appearance and the concept of banks the architectural style of the older bank is better than that of the modern bank belief makes the older generation think that the modern bank is unreliable
Question: My father' s response to the bank building at 43rd Street and Fifth Avenue in New York city was immediate and definite: "You won' t catch me putting my money in there!" he declared, "Not in that glass box. " Of course, my father is a gentleman of the old school, a member of the generation to whom a good deal of modern architecture is upsetting, but I believe that his negative response was not so much to the architecture as to a violation of his concept of the nature of money. In his generation money was thought of as a real commodity  that could be carried, or stolen. Therefore, to attract the custom of a sensible man, a bank had to have heavy walls, barred windows, and bronze doors, to make sure of the fact, however, untrue, that money would be safe inside. If a building' s design made it appear strong, the institution was necessarily reliable, and the meaning of the heavy wall as an architecture symbol showed the general attitude toward money. But the attitude toward money has, of course, changed. Except pocket money, cash of any kind is now rarely used; money as a tangible commodity has largely been replaced by credit. The banker no longer offers us a safe: he offers us a service in which the most valuable factor is the creativity for the invention of large numbers. It is in no way surprising, in view of this change in attitude, that we are witnessing the disappearance of the heavy-walled bank. Just as the older bank emphasized its strength, this bank by its architecture is proud of imaginative powers. The main idea of this passage is that   _  .
A. money is not as valuable as it was in the past
B. changes have taken place in both the appearance and the concept of banks
C. the architectural style of the older bank is better than that of the modern bank
D. belief makes the older generation think that the modern bank is unreliable
Answer: