Respuesta :

"First reading" is the event among the choices that are given in the question that must be introduced if a rider is attached to a bill. The correct option among all the options that are given in the question is the first option or option "A". I hope that this is the answer that has come to your help.

Answer:

First reading

Explanation:

If a rider is attached to a bill, it must be introduced before the first reading. The first reading  of a bill refers to the moment when this is introduced to a legislature. This is called the "first reading" as there are various stages that a bill is subjected to as it goes through the process of becoming legislation.