**Core Concept**
Genital tuberculosis is a rare form of extrapulmonary tuberculosis that primarily affects the female reproductive system. It is usually a result of hematogenous spread from a pulmonary focus. The disease can cause significant morbidity due to its potential to cause infertility, chronic pelvic pain, and other reproductive complications.

**Why the Correct Answer is Right**
The most common site of genital tuberculosis in women is the fallopian tubes, also known as salpingitis. This occurs due to the direct spread of tuberculosis bacilli from the bloodstream into the fallopian tubes. The fallopian tubes are highly vascular and have a rich blood supply, making them a common site for hematogenous spread of tuberculosis. The involvement of the fallopian tubes can lead to chronic inflammation, scarring, and eventual occlusion, resulting in infertility.

**Why Each Wrong Option is Incorrect**
**Option A:** Ovarian tuberculosis is less common than fallopian tube involvement but can still occur. However, it is not the most common site.
**Option B:** Uterine tuberculosis is rare and typically occurs in conjunction with fallopian tube involvement. It is not the most common site of genital tuberculosis.
**Option C:** Vaginal tuberculosis is extremely rare and usually occurs in conjunction with other forms of genital tuberculosis. It is not the most common site.

**Clinical Pearl / High-Yield Fact**
The Asherman syndrome, characterized by intrauterine adhesions, can be a complication of genital tuberculosis. It is essential to consider this condition in patients with a history of pelvic surgery or genital tuberculosis.

**Correct Answer: C. Fallopian tubes.