To determine which type of motor is used in the axis or spindle drives of CNC machine tools, let's analyze the characteristics of each option:

1. Induction Motor: These motors are generally used in applications where speed control is not very precise, as they are not easily controlled in terms of speed and position. Induction motors are not typically used for CNC machine drives, where precise control is necessary.
2. Stepper Motor: These motors convert digital pulses into mechanical rotation, providing precise position control. They are commonly used in CNC machines for controlling axes due to their ability to perform incremental movements accurately. However, they are not often used for spindle drives, as they are less efficient at high speeds.
3. DC Servo Motor: These motors provide precise speed and position control, making them suitable for both axis and spindle drives in CNC machines. They offer high torque and efficiency, especially suitable for applications demanding precise control.
4. Linear Servo Motor: These are specialized for linear motion applications and are not typically used in the rotational drives of CNC machine tools.

From the analysis above, stepper motors (option B) are suitable for axis control, and DC servo motors (option C) are excellent for both axis and spindle drives due to their precise control capabilities.

This aligns with the correct answer: B and C only. Hence, stepper motors and DC servo motors are the correct selections for use in CNC machine tools.