Which form of herpes is usually sexually transmitted and affects from the waist down?

Herpes type II is the form of herpes that is primarily associated with sexual transmission and typically affects the genital area. It is most commonly responsible for genital herpes, which manifests as painful sores or lesions in the genital region, around the anus, and sometimes on the inner thighs. The transmission usually occurs through intimate sexual contact with an infected individual, leading to its designation as a sexually transmitted infection (STI).

In contrast, Herpes type I is generally associated with oral herpes, which causes cold sores around the mouth but can also lead to genital infection through oral-genital contact. Genital warts are caused by different strains of the human papillomavirus (HPV) and are not caused by herpes viruses at all. Zoster, or shingles, is a reactivation of the varicella zoster virus, which causes chickenpox and is not sexually transmitted. Therefore, Herpes type II is clearly the correct answer as it specifically matches the criteria of being sexually transmitted and affecting areas from the waist down.