Answer: A bank uses the resources of many customers to help finance loans to a few.
Explanation: A collective immunity is like a group of people being immune. And if all those people get immunized, then the people who can't physically get immunized will be okay. Now think of the collective immunity as a bunch of people that keep their money in a bank. Someone needs a loan from that bank because they don't have enough money, the "collective group" of people are helping that person out.
