The incidence rate of a disease is five times greater in women than in men, but the prevalence rates show no sex difference. The best explanation is that :

Correct answer in review question: B. the case-fatality for this disease is greater in women. Again no explanation in the answer section how the authors arrived at this answer to the question, and why not the duration of this disease shorter in men?? I get frustrated trying to comprehend how they come to their practice exercise answers.