**Core Concept**
Ridge soreness in denture patients is a common issue related to the underlying bone density and the adaptation of the mucosa to the denture. The primary concern is the resorption of the alveolar bone, which affects the denture-bearing area.

**Why the Correct Answer is Right**
The correct answer is related to the concept of alveolar bone resorption. When dentures are not properly fitted or maintained, the alveolar bone undergoes resorption, leading to discomfort and soreness. This is because the denture-bearing area is subjected to constant pressure, which stimulates the bone remodeling process. The resorption of bone tissue results in a decrease in the denture-bearing area, causing soreness and discomfort.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not address the underlying cause of ridge soreness. While denture trauma can cause soreness, it is not the primary concern in this context.
**Option B:** This option is incorrect because it is a common cause of denture soreness, but not the primary concern related to ridge soreness. Denture irritation can be managed with adjustments to the denture or the use of a denture adhesive.
**Option C:** This option is incorrect because it is a condition that affects the mucosa, but not directly related to the alveolar bone resorption that causes ridge soreness.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that regular denture adjustments and proper denture care can help prevent alveolar bone resorption and reduce the risk of ridge soreness.

**Correct Answer: C. Alveolar bone resorption.