The answer is a i believe
The correct answer is letter A. Pre-existing conditions are usually the exclusions of health care programs available in most societies. This is the reason why there are a lot of lawsuits filed against healthcare companies who do not fairly adhere with the interests of their clients/patients.
For example, people who have anorexia severely reduce their food intake to lose weight. People who have bulimia eat an excessive amount of food in a short period of time, then purge or use other methods to prevent weight gain.