Is a motorcyclist permitted to drive at the side of another motorcycle?

1. No, he is only permitted to drive at the side of a private passenger car.
2. No, he is only permitted to drive at the side of a commercial vehicle transporting passengers.
3. Correct answer: No, but he is permitted to overtake it.
4. Absolutely not.

WhyRiding side by side with another motorcycle is not allowed, but overtaking it is.