Geography

There is no river named Ontario; however, Ontario is a province in Canada. The closest correct association is Canada, making option B the best choice.

A 'Doab' is a geographical term referring to a tract of land lying between two converging rivers. The word comes from Persian, where 'do' means two and 'ab' means water or river.

Europe has the highest number of countries among all continents, with around 44 to 50 depending on definitions, which is more than Africa, Asia, or North America.

Iguazu Falls is considered the largest waterfall system in the world by total width and number of individual falls, surpassing Angel Falls, Victoria Falls, and Niagara Falls. Angel Falls is the tallest single waterfall, but not the largest system.

Belgium is located in Western Europe, bordered by France, Germany, Luxembourg, and the Netherlands, making 'West' the correct regional descriptor.

The Atacama Desert is located in South America, primarily in northern Chile. It is known as one of the driest places on Earth.

Africa is the only continent that spans all four hemispheres: Northern, Southern, Eastern, and Western. It crosses the Equator and the Prime Meridian, placing parts of it in each hemisphere.

The Northern Hemisphere contains the majority of the world's landmass and most of the global population, making it more populated than the Southern Hemisphere and the Western Hemisphere. The Eastern Hemisphere includes populous regions but is not a hemisphere defined by population density as clearly as the Northern Hemisphere.

A peninsula is a piece of land that is surrounded by water on three sides, distinguishing it from bays, lagoons, and erosion, which are different geographical features or processes.

Earth is commonly divided into four hemispheres: Northern, Southern, Eastern, and Western. This division helps in geographical and climatic studies.