Which STIs are known to be incurable?

The correct choice identifies diseases that are known to be incurable. HIV (Human Immunodeficiency Virus) is a chronic infection that attacks the immune system and, while treatments exist to manage the virus and maintain quality of life, there is currently no cure. Similarly, HPV (Human Papillomavirus) can lead to various health issues, including genital warts and certain cancers, and while many strains may clear on their own, there is no cure for the infection itself.

In contrast, while chlamydia and gonorrhea, as well as syphilis, can have serious health implications, they are treatable and often curable with appropriate antibiotic therapy. Herpes, while treatable and manageable with antiviral medications, remains a lifelong infection without a cure. Therefore, the combination of HIV and HPV accurately represents incurable STIs within the context of the provided options.