**Explanation:**

Metal molds are used in various casting processes to create intricate and accurate shapes for the production of metal components. Among the given options, metal molds are used in the die casting process.

**Die Casting Process:**
Die casting is a metal casting process that involves forcing molten metal under high pressure into a mold cavity. The mold cavity is created using a metal mold, which is typically made of steel or another durable material. The metal mold consists of two halves, the stationary half called the "die" and the movable half called the "die casting machine."

**Advantages of Metal Molds in Die Casting:**
Metal molds offer several advantages in the die casting process, making it a preferred choice for high-volume production of complex-shaped components:

1. **Accuracy and Precision:** Metal molds provide excellent dimensional accuracy and repeatability, ensuring consistent quality in the castings produced. The high precision of metal molds allows for the production of intricate and detailed components.

2. **Durability:** Metal molds are made of materials like steel, which are highly durable and can withstand the high pressures and temperatures involved in the die casting process. This ensures the longevity of the mold and allows for multiple production cycles.

3. **Heat Transfer:** Metal molds have good thermal conductivity, allowing for efficient heat transfer between the molten metal and the mold. This facilitates rapid solidification and reduces cycle times, increasing the overall productivity of the die casting process.

4. **Surface Finish:** Metal molds provide a smooth and high-quality surface finish to the cast components. This eliminates the need for additional finishing operations and reduces post-processing requirements.

5. **Cost-Effective:** Although metal molds have higher initial costs compared to other types of molds, they offer long-term cost savings due to their durability and high production rates. The fast cycle times and minimal maintenance requirements make metal molds a cost-effective choice for large-scale production.

In conclusion, metal molds are used in the die casting process due to their ability to provide accurate, precise, and high-quality castings with excellent surface finish. These molds ensure the efficiency, productivity, and cost-effectiveness of the die casting process.