The boy's incorrigible behaviour puzzled his sister

The word incorrigible in this sentence means?

a) appalling

b) reformed

c) incurable

d) frustrated

e) none of these

Answer: C. (Incurable)

Explanation: Incorrigible means beyond reforms, cannot change or be improved upon. When you say someone has incorrigible behavior, you are simply saying that the person's behavior is bad beyond correction or reform. You have tried all you can to correct that behavior yet the person cannot stop behaving in that way. In the question, he can't be cured of that bad thing they do. He is Incurable.