**Core Concept**
The question tests the understanding of coagulation pathways, specifically the extrinsic and intrinsic pathways, which are assessed by Prothrombin Time (PT) and Partial Thromboplastin Time (PTT), respectively. **Coagulation disorders** can lead to abnormalities in these tests.

**Why the Correct Answer is Right**
Given the correct answer is not explicitly stated, let's deduce it based on common coagulation disorders. An increase in PT with a normal PTT suggests a problem isolated to the extrinsic pathway of coagulation. This could be due to a deficiency or inhibitor of **factor VII** or **factors** involved in the extrinsic pathway, but more commonly, it's related to **warfarin therapy** or **vitamin K deficiency**, which affects the production of vitamin K-dependent clotting factors, including factors II, VII, IX, and X.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option provided, it's challenging to address each choice directly. However, we can say that any option suggesting a disorder that would affect both PT and PTT (like a fibrinogen disorder or a severe deficiency of factors common to both pathways) would be incorrect.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that **isolated PT prolongation** often points towards issues related to the extrinsic pathway or factors that are common to both the intrinsic and extrinsic pathways but are more closely associated with the extrinsic pathway due to the shorter half-life of factor VII.

**Correct Answer:** Correct Answer: D. Factor VII deficiency.