Which of the following natural features would likely exist in a densely populated area of the world?

is fertile farmland

Since you haven't provided any choices, the answer is "fertile farmland."

Explanation:

In order to learn more about the answer, it is best to know the meaning of "population density" first.

Population Density - This is defined as the number of population per unit area. For example, a population of 50 people living in an area of 10,000 square meters. This means that one person lives in every 200 square meters.

Densely populated area means many people live in that area. There is always a reason why people flock to a place. Oftentimes, it is because of economic reasons. For example, the area is rich in natural resources or the climate in the area is favorable for farming or crop production. This explains the answer which is fertile farmland.

Additional Information:

Other than natural reasons, a densely populated area also has a stable government that's why many people live in that place. They also live close to each other, so this establishes close social relationships. There are also plenty of job opportunities for them.