Answer: need
Step-by-step explanation:
Nina is stating the need for safety for the children and she gives all the justifiable reasons why this is actual a need.
Her speech has evidence showing what has happened previously due to the lack of safety in automobiles which transport children.
Her speech is credible enough to persuade people to see this need of automobile safety .
She is giving them evidence with reason and investigated facts to show how much this is a needed solution .