**Core Concept**
Liver plays a crucial role in the synthesis of various proteins, including clotting factors. The liver synthesizes all the coagulation factors, except for factor VIII, which is synthesized in the endothelial cells. Abnormalities in the synthetic function of the liver can lead to decreased levels of these clotting factors, resulting in coagulopathy.

**Why the Correct Answer is Right**
When liver synthetic function is compromised, the production of clotting factors is impaired, leading to decreased levels of these factors. This results in a prolongation of the prothrombin time (PT), which is a measure of the time taken for blood to clot. The prolongation of PT is a reflection of the decreased levels of clotting factors, such as prothrombin (factor II), fibrinogen (factor I), and other factors involved in the coagulation cascade. This is a critical consequence of liver dysfunction, as it can lead to bleeding tendencies in affected individuals.

**Why Each Wrong Option is Incorrect**
**Option B:** Hyperbilirubinemia is a result of impaired conjugation of bilirubin in the liver, not synthetic function. It is a sign of liver dysfunction, but not directly related to the synthetic function of the liver.

**Option C:** Acute phase reactants, such as C-reactive protein, are actually increased in liver dysfunction, not decreased. They are produced in response to inflammation and infection, and their levels are often elevated in patients with liver disease.

**Option D:** Disturbance in Kupffer cells is related to phagocytic function, not synthetic function. Kupffer cells are involved in the clearance of bacteria, dead cells, and other foreign particles, but their dysfunction does not directly affect the synthetic function of the liver.

**Clinical Pearl / High-Yield Fact**
The liver synthesizes all the coagulation factors, except for factor VIII, which is synthesized in the endothelial cells. This is a critical aspect of liver physiology, as abnormalities in liver synthetic function can lead to coagulopathy and bleeding tendencies.

**✓ Correct Answer: A. |PT**