**Core Concept**
Gerstmann's Syndrome is a neurological disorder characterized by a classic tetrad of symptoms resulting from lesions in the dominant parietal lobe, particularly the angular gyrus. This syndrome is associated with difficulties in calculation, finger agnosia, left-right disorientation, and agraphia.

**Why the Correct Answer is Right**
The classic symptoms of Gerstmann's Syndrome are attributed to the involvement of the angular gyrus, a critical region in the parietal lobe responsible for processing spatial information. The angular gyrus is also involved in the integration of sensory information from various modalities, including visual, tactile, and proprioceptive inputs. The tetrad of symptoms is thought to result from the disruption of these complex neural networks.

**Why Each Wrong Option is Incorrect**
**Option A:** Calculation difficulties are a key feature of Gerstmann's Syndrome, making this option incorrect.
**Option B:** Finger agnosia is another characteristic symptom of Gerstmann's Syndrome, so this option is also incorrect.
**Option C:** Left-right disorientation is a fundamental component of the syndrome, thus making this option incorrect as well.

**Clinical Pearl / High-Yield Fact**
Gerstmann's Syndrome is often associated with lesions in the dominant parietal lobe, typically resulting from strokes or traumatic brain injuries. Early recognition and diagnosis of this syndrome are crucial for implementing targeted rehabilitation strategies to improve cognitive and motor function.

**Correct Answer:** D