In: Economics
When firms participate in group health insurance for all employees, it:
| A) raises rates for unhealthy people. | 
| B) prevents unhealthy people from "selecting out," to the detriment of healthy people. | 
| C) increases the amount of information available to insurers about the population. | 
| D) may lower rates for all people to the extent that it keeps healthy people in the pool. | 
| E) raises rates for everyone, because it brings unhealthy people into the pool. | 
In a group insurance policy people, no matter if they are healthy or unhealthy is part of the pool. It allows the insurer to pool its resources form a large number of people and lower the rates.
The answer is "May lower rates for all people to the extent that it keeps healthy people in the pool."