This is an area in Australia with a high number of people, or high population density, living close together. What is it?

Australia's population density as of June 2016 was 3.1 people per square kilometre. Among the states and territories, the Australian Capital Territory (ACT) had the highest population density, at 171 people per sq km

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.