**Explanation:**

Mixies, also known as mixer grinders, are kitchen appliances used for grinding and blending purposes. They typically consist of a motor and a set of rotating blades or jars.

The motor used in mixies is a **universal motor**.

**Universal Motor:**
A universal motor is a type of electric motor that can operate on both AC and DC power. It is a series-wound motor, meaning that the field winding and the armature winding are connected in series. This allows the motor to have high starting torque and variable speed control.

**Advantages of Universal Motors:**
- High starting torque: The universal motor is capable of delivering high starting torque, which is necessary for grinding and blending applications.
- Variable speed control: The speed of the motor can be easily controlled by varying the input voltage or by using a speed controller. This is important in mixies as different ingredients require different speeds for effective grinding.
- Compact size: Universal motors are compact in size, making them suitable for use in small kitchen appliances like mixies.
- Cost-effective: Universal motors are relatively inexpensive compared to other types of motors, making them a popular choice for mixies and similar appliances.

**Other Motor Options:**
- **Repulsion Motor:** Repulsion motors are generally used in applications where high starting torque is required, such as in elevators and hoists. However, they are not commonly used in mixies.
- **Reluctance Motor:** Reluctance motors are primarily used in applications requiring high torque at low speeds, such as in industrial machines. They are not commonly used in mixies.
- **Hysteresis Motor:** Hysteresis motors are synchronous motors that operate based on hysteresis losses in the rotor. They are typically used in applications requiring smooth and constant speed, such as in clocks and record players. They are not commonly used in mixies.

Therefore, the correct answer is option **D) Universal Motor**, as it is the most suitable motor for mixies due to its high starting torque, variable speed control, compact size, and cost-effectiveness.