Strongest research design for a study which is hoping to determine cause and effect?

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.

yes

it is because 3 because the citizen the northern democratic party watned the warning on red to blue because it is purple. lol