Answer:
Decision making under risk
Explanation:
The reason is that Selena faces one of its biggest risks which is that if she will proceed with the surgery then she might loose her arm. Loosing arm is the risk here. Remember that risk is vulnerability of undesired outcome and which can be measured. And here the risk is the undesired outcome of loosing arm which is measureable in percentage. The chances of loosing arm is 30% and taking decision to proceed with taking this risk of loosing arm is "Decision making under risk".