Geography

India has the largest area under cultivation globally, with approximately 195 million hectares of land used for crops. This surpasses the cultivated areas of the USA, China, and Pakistan. India's vast agricultural land is due to its large rural population and extensive farming activities, making it the country with the largest cultivated area.

An archipelago is defined as a group or chain of separate islands clustered together in a body of water. They are not necessarily interconnected physically, but are geographically close.

A basin is a lower area of land, typically surrounded by higher land, where water can collect. This distinguishes it from high areas or deep parts of rivers or oceans.

The Strait of Gibraltar is known as the key to the Mediterranean Sea because it is the narrow passage that connects the Atlantic Ocean to the Mediterranean, controlling access to the sea.

Orography is the branch of physical geography that studies the formation, structure, and features of mountains. The other options refer to different fields: Cartography is map-making, Palaeogeography studies ancient geographical features, and Oceanography studies oceans.

Tundra refers to the biome found in high latitude regions characterized by short, cool summers and permafrost, which prevents tree growth. This matches the description given in the question.

An ice mass covering more than 50,000 square kilometers is classified as an ice sheet. Ice fields and ice caps are smaller, and glacier erosion is a process, not a type of ice mass.

The term 'Blue River' refers to multiple rivers and locations, but the most notable and commonly referenced Blue Rivers are located in the United States. There is a statutory town named Blue River in Colorado, and a Blue River tributary of the Colorado River also in Colorado. Additionally, there is a Blue River in Oklahoma and a Blue River flowing through Kansas and Missouri. None of the other options (China, South Africa, Austria) are commonly associated with a notable Blue River. Therefore, the correct answer is the U.S.

Tarawa is the capital of Kiribati, located in the central Pacific Ocean. The other options are not recognized as capitals or major locations in Kiribati.

Loess is a fine, yellowish or buff-colored silt or dust deposited by wind, known for its fertility and often found in agricultural regions. Alluvium refers to sediments deposited by rivers, and sediment is a general term for particles deposited by water, wind, or ice.