The cross-over distortion occurs in class B push-pull amplifiers. The following statements are made in regard to cross-over distortion.
1. It arises from the non-linearity of collector characteristics.
2. It would not occur if the base current were sinusoidal.
3. It would not occur if the base voltage were sinusoidal.
4. In the region of small input currents the output is much smaller than it would be if the response output current were linear.
Of these four statements, the true statements are: