**Core Concept**
In the context of computer-aided design/computer-aided manufacturing (CAD/CAM) inlay preparation, undercuts can pose a challenge for accurate impression capture and successful restoration fit. Therefore, it is crucial to address these undercuts before proceeding with the CAD/CAM process.

**Why the Correct Answer is Right**
The dentist is responsible for identifying and blocking out undercuts in the cavity preparation after the final shaping stage. This is done using a combination of burs and instruments to remove any undercuts that may compromise the fit of the inlay. This step ensures that the optical impression taken by the CAD/CAM system accurately captures the prepared cavity, allowing for accurate fabrication of the inlay.

**Why Each Wrong Option is Incorrect**
**Option A:** The laboratory technician is not responsible for blocking out undercuts in the cavity preparation, as this step is typically completed by the dentist before sending the case to the lab.

**Option B:** While the laboratory technician prepares the wax pattern, they do not address undercuts in the cavity preparation, which have already been blocked out by the dentist.

**Option C:** The CAD/CAM system does not automatically block out undercuts, as this requires a precise and controlled removal of material by the dentist to ensure accurate impression capture.

**Option D:** Dentist preparation of the wax pattern is not the same as blocking out undercuts in the cavity preparation, which is a distinct step completed before wax pattern preparation.

**Clinical Pearl / High-Yield Fact**
It is essential to communicate clearly with the laboratory technician regarding any undercuts that have been blocked out to prevent misinterpretation and ensure accurate fabrication of the inlay.

**✓ Correct Answer: A. Dentist after final cavity preparation stage**