Final answer:
This question is about the risks of developing cancer after specific time periods for individuals with atypical hyperplasia.
Step-by-step explanation:
The subject of this question is Medicine. The question asks about the risk of developing cancer after certain time periods for individuals with atypical hyperplasia. This is a medical term used to describe abnormal cell growth in body tissues.
The risk of developing cancer varies over time for individuals with atypical hyperplasia. According to the given options, the risk of Ca after 4 years is b) Risk of Ca after 9 years c) Risk of Ca after 19 years, d) Risk of concomitant Ca. It's important to consult with a healthcare professional for a more accurate assessment of an individual's risk.