Final answer:
Fear of abandonment, frustration, and emotional pain are three possible emotional effects that may influence the behavior of a person with a serious illness.
Step-by-step explanation:
Three possible emotional effects that may influence the behavior of a person with a serious illness are fear of abandonment, frustration, and emotional pain (option a). When someone is seriously ill, they may have a heightened fear of being abandoned due to their illness. They may also experience frustration and emotional pain as they navigate the challenges and uncertainties associated with their illness.