**Core Concept**
Papilledema is a condition characterized by swelling of the optic disc due to increased intracranial pressure. Fundoscopic examination is essential for diagnosing papilledema, and several key features are typically observed. Understanding these features is crucial for accurate diagnosis.

**Why the Correct Answer is Right**
The correct answer is B. Deep physiological cup, because in papilledema, the physiological cup is typically shallow or obliterated. The physiological cup is the area within the optic disc where the nerve fibers exit, and its depth is normally about 0.1-0.2 mm. In papilledema, the increased intracranial pressure causes the optic disc to swell, leading to a reduction in the depth of the physiological cup. This is a critical feature that distinguishes papilledema from other conditions.

**Why Each Wrong Option is Incorrect**
**Option A:** Ill-defined disc margin is actually a feature of papilledema. The increased intracranial pressure causes the optic disc to swell, leading to an ill-defined or blurred disc margin.
**Option C:** Absent venous pulsation is also a feature of papilledema. The increased intracranial pressure causes the veins to become compressed, leading to a reduction or absence of venous pulsation.
**Option D:** Bending of blood vessels is another feature of papilledema. The increased intracranial pressure causes the blood vessels to become stretched and bent, leading to a characteristic "blown" appearance.

**Clinical Pearl / High-Yield Fact**
In addition to the features mentioned above, papilledema is often associated with a "cotton-wool spot" – a white, fluffy exudate on the surface of the retina. This is caused by the leakage of fluid from the damaged optic nerve head.

**✓ Correct Answer: B. Deep physiological cup**