Why can't molecularity of any reaction be equal to zero?

Why can molecularity of any reaction not be equal to zero?

Molecularity of any reaction is not equal to zero. Why ?

Molecularity of a reaction cannot be zero.

Molecularity of a reaction is never zero. Explain?

What is meant by molecularity of a reaction ? Why the molecularity of a reaction rarely exceeds three?

(A) Molecularity has no meaning for a complex reaction. (R ) The overall molecularity of a complex reaction is equal to the molecularity of the slow step.