**Core Concept**
Retinitis pigmentosa (RP) is a group of genetic disorders affecting the retina's ability to respond to light, leading to progressive vision loss. The condition primarily affects the rod photoreceptors, causing night blindness and peripheral vision loss.

**Why the Correct Answer is Right**
In RP, the degeneration of rod photoreceptors leads to a characteristic fundus appearance. The retina develops a "bone-spicule" appearance due to the atrophy of the retinal pigment epithelium (RPE) and the accumulation of pigment in the mid-peripheral retina. This fundus appearance is a result of the degeneration of the photoreceptors and the secondary effects on the RPE.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not describe the characteristic fundus appearance of RP. The "salt and pepper" appearance is more commonly associated with age-related macular degeneration.

**Option B:** This option is incorrect as it does not accurately describe the fundus appearance of RP. The "cottage cheese" appearance is more commonly associated with diabetic retinopathy.

**Option C:** This option is incorrect as it does not describe the characteristic fundus appearance of RP. The "cherry red spot" is more commonly associated with macular dystrophies.

**Clinical Pearl / High-Yield Fact**
A key feature of RP is the presence of night blindness due to the degeneration of rod photoreceptors. This symptom often precedes the development of peripheral vision loss.

**Correct Answer:** C.