**Core Concept**
Retinal detachment occurs when the retina separates from the underlying retinal pigment epithelium, leading to visual impairment. It can be caused by various factors, including trauma, inflammation, or age-related degeneration.

**Why the Correct Answer is Right**
The commonest type of retinal detachment is rhegmatogenous retinal detachment, which is caused by the formation of a retinal tear or hole. This allows fluid to seep under the retina, leading to its separation from the underlying retinal pigment epithelium. The vitreous gel that fills the eye can also cause traction on the retina, exacerbating the detachment.

**Why Each Wrong Option is Incorrect**
**Option A:** Tractional retinal detachment is a less common type of retinal detachment that occurs due to scarring or fibrosis in the vitreous gel, typically seen in diabetic retinopathy or other conditions causing vitreoretinal traction. It is not the most common type.
**Option B:** Exudative retinal detachment is caused by the accumulation of fluid under the retina due to various conditions, such as tumors, inflammatory diseases, or retinal vascular diseases. It is a less common type of retinal detachment compared to rhegmatogenous retinal detachment.
**Option C:** Choroidal neovascularization can cause subretinal fluid accumulation and retinal detachment, but it is not the most common type of retinal detachment.

**Clinical Pearl / High-Yield Fact**
Rhegmatogenous retinal detachment is often associated with posterior vitreous detachment (PVD), where the vitreous gel separates from the retina, increasing the risk of retinal tears and detachment.

**Correct Answer:** C.