PLEASE HELP Can someone fill in the last one?

Hmm there are many things such as demographic transitional models, and epidemiological transition models, population pyramids, etc.

Explanation:

the models and population pyramids both help someone learn about an area at a given time. We can see how developed a country is by looking at birth and death rates, gender ratios, etc. For example, less children and a longer life expectancy means a more developed country, seeing as people live longer so there is no need for all those kids, and women are being given more education so it is less likely for them to want to stay home, but rather go out and get an education (:

answer; the above statement is (true);

answer; /// all of the above;