**Core Concept**
Ludwig's angina is a severe, potentially life-threatening infection of the submandibular space, characterized by rapid swelling of the tissues in the neck. The infection often involves the submandibular and sublingual glands, leading to significant edema and potential airway compromise.

**Why the Correct Answer is Right**
The correct answer involves understanding the typical clinical features of Ludwig's angina. This condition is characterized by severe pain, difficulty swallowing, and a firm, non-tender swelling in the submandibular region. The patient may also experience dysphagia, dyspnea, and a feeling of impending airway obstruction.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Ludwig's angina is typically characterized by a firm, non-tender swelling in the submandibular region, not a fluctuant swelling.

**Option B:** This option is incorrect because Ludwig's angina often involves the submandibular and sublingual glands, leading to significant edema and potential airway compromise.

**Option C:** This option is incorrect because Ludwig's angina is not usually associated with a "woody" hard swelling, which is more characteristic of a different condition.

**Clinical Pearl / High-Yield Fact**
A key clinical feature of Ludwig's angina is the potential for rapid progression to airway compromise, making prompt recognition and management essential.

**Correct Answer:** C.