**Core Concept**
Extended spatulation of Glass Ionomer Cement (GIC) is a technique used to improve the adaptation of GIC to the tooth surface, especially in deep cavities. This process involves the use of a spatula to shape and adapt the GIC to the cavity walls, ensuring a tight seal and preventing leakage.

**Why the Correct Answer is Right**
The correct answer is the one that describes the correct technique for extended spatulation of GIC. This involves using a spatula to shape and adapt the GIC to the cavity walls, ensuring a tight seal and preventing leakage. The correct technique helps to prevent the GIC from shrinking or expanding, which can lead to microleakage and secondary caries.

**Why Each Wrong Option is Incorrect**
**Option A:** This option may describe a technique that involves using a brush to apply the GIC, which is not an effective method for extended spatulation.

**Option B:** This option may describe a technique that involves using a high-speed drill to shape the GIC, which can damage the tooth structure and compromise the seal.

**Option C:** This option may describe a technique that involves using a GIC with a high powder-to-liquid ratio, which can lead to a weak and brittle restoration.

**Clinical Pearl / High-Yield Fact**
It is essential to use the correct technique for extended spatulation of GIC to ensure a tight seal and prevent microleakage. The correct technique involves using a spatula to shape and adapt the GIC to the cavity walls, ensuring a smooth and even surface.

**Correct Answer:** D.