**Core Concept**
Primary biliary cirrhosis (PBC) is a chronic liver disease characterized by the progressive destruction of intrahepatic bile ducts, leading to cholestasis and ultimately cirrhosis. The clinical manifestations of PBC are primarily related to the accumulation of bile salts in the bloodstream and the resulting liver damage.

**Why the Correct Answer is Right**
The two most important clinical features of PBC are pruritus and fatigue. Pruritus is a common symptom of PBC, resulting from the accumulation of bile salts in the skin, which activates the sensory nerve endings and leads to intense itching. Fatigue is another hallmark symptom of PBC, likely due to the accumulation of bile salts and the resulting liver dysfunction, which impairs the body's ability to produce energy. The correct answer highlights the importance of these two symptoms in the diagnosis and management of PBC.

**Why Each Wrong Option is Incorrect**
**Option A:** Jaundice is not a universal feature of PBC and may not be present in the early stages of the disease. While jaundice can occur in advanced cases, it is not a distinguishing characteristic of PBC.
**Option B:** Clubbing is a feature of other liver diseases, such as primary biliary cirrhosis is not typically associated with clubbing. It is more commonly seen in diseases that cause chronic hypoxia or malabsorption.
**Option C:** Hematemesis is not a typical feature of PBC, as the disease primarily affects the intrahepatic bile ducts rather than the blood vessels. Hematemesis is more commonly associated with conditions that cause bleeding from the upper gastrointestinal tract.
**Option D:** While weight loss can occur in PBC, it is not a specific or sensitive feature of the disease. Fatigue and pruritus are more distinctive symptoms of PBC.

**Clinical Pearl / High-Yield Fact**
PBC often presents with a "fatigued" patient with intense pruritus, and the disease should be suspected in patients with unexplained fatigue and pruritus, especially in the absence of other obvious causes.

**Correct Answer: A. Generalized pruritus**