Consider the following statements regarding a stepper motor:
1. The rotation angle of the motor is proportional to the input pulse.
2. The motor has full torque at standstill.
3. Speed and electric control signal of the motor vary mutually linearly.
Which of the above statements are correct?
(a) 1 and 2 only (b) 1 and 3 only
(c) 2 and 3 only (d) 1, 2 and 3