## **Core Concept**
The question pertains to the clinical manifestations of a specific condition characterized by skin and tongue changes. The symptoms described, such as doughy skin and woody induration of the tongue, are indicative of a particular disorder affecting connective tissue.

## **Why the Correct Answer is Right**
The correct answer, **C. Scleroderma**, is right because scleroderma, also known as systemic sclerosis, is a chronic autoimmune disease characterized by thickening and hardening of the skin and involvement of internal organs. The skin changes in scleroderma can progress from being edematous and doughy to becoming thickened and tight, leading to limited mobility. The tongue can become woody and indurated due to the deposition of collagen, a hallmark of the disease.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not correspond to a condition known for causing doughy skin and woody induration of the tongue.
- **Option B:** This option is incorrect as it does not match a condition associated with the described symptoms.
- **Option D:** This option is incorrect because it represents another condition not typically associated with doughy skin and a woody tongue.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that scleroderma can present with a range of skin manifestations, from early edematous changes to late-stage atrophic and fibrotic changes. The involvement of the tongue, leading to difficulties with speech and swallowing, is a notable feature that can significantly impact the quality of life.

## **Correct Answer:** . C. Scleroderma