The correct answer is A- earn money
Indeed, the doctor knows that the aunt’s wound can be cured quite quickly. However, he pretends the contrary and keeps visiting her and treating her symptoms for many years. When his son becomes a doctor, he brings him along and his son discovers that the wound could have been cured very easily a long time ago. His father admits to it but explains to him that thanks to the many visits; he was able to pay for his son’s medical school education.