Which two diseases currently have no known cure?

The correct choice highlights that both herpes and AIDS are viral infections that, despite advances in medical science and treatment options, currently have no known Cure.

Herpes, caused by the herpes simplex virus (HSV), can be managed with antiviral medications to suppress outbreaks and reduce transmission, but there is no cure that eliminates the virus from the body. Similarly, HIV, the virus that leads to AIDS, can be treated effectively with antiretroviral therapy, which allows individuals to live long and healthy lives. However, this treatment does not eradicate the virus, thus making it currently incurable.

In contrast, the other options include diseases that either have effective treatments available or are not categorized as incurable in the same sense. The flu and the common cold are caused by viruses that the body typically clears on its own, and antiviral treatments can help mitigate symptoms and duration. Hepatitis and tuberculosis, while serious, can be treated and often cured with appropriate medical care. Diabetes and arthritis are chronic conditions managed through lifestyle changes and medications, rather than being classified strictly as diseases without cures.