Thimphu or Thimphu is the capital and largest city of the mountain nation of Bhutan.

Congo is the only major river which crosses the equator twice. It is the second largest river in Africa after Nile and the second largest river in the world.

The steppe grassland is primarily found in (A) Asia. The Eurasian Steppe, also known as the Great Steppe, is a vast expanse of grassland that stretches from Eastern Europe to Siberia in Asia. It is one of the world's largest temperate grasslands and spans several countries, including Russia, Ukraine, Kazakhstan, and Mongolia.

The ocean situated between the continent of Africa and Europe is the (C) Mediterranean Sea. The Mediterranean Sea is a large body of water that is connected to the Atlantic Ocean through the Strait of Gibraltar. It separates Southern Europe from Northern Africa and serves as a critical maritime route and cultural crossroads.

Tel Aviv is the major city of (B) Israel. It is one of the largest and most populous cities in Israel, located on the country's Mediterranean coastline. Tel Aviv is a vibrant and modern city known for its cultural richness, economic activity, and diverse population. It is a center for technology, innovation, and the arts in the region.

The river that is often referred to as the "lifeline of European trade" is (B) Rhine. The Rhine River is a major waterway in Europe that flows through several countries, including Germany, France, the Netherlands, Switzerland, Austria, and Liechtenstein. It plays a crucial role in the transportation of goods and is an important trade route, earning it the designation as the "lifeline of European trade."

The world's highest waterfall is located in (B) Venezuela. The waterfall is named Angel Falls (Salto Ángel in Spanish), and it is situated in the Canaima National Park in the Gran Sabana region of Venezuela. Angel Falls is renowned for its impressive height, with a continuous drop of about 3,212 feet (979 meters) and a total height of 3,281 feet (1,000 meters).

The headquarters of the International Atomic Energy Agency (IAEA) is located in (B) Vienna, Austria. Vienna has been the headquarters of the IAEA since its establishment in 1957. The city's selection as the headquarters reflects its role as a neutral and international city, making it a suitable location for an agency tasked with promoting the peaceful use of nuclear energy and preventing its use for military purposes.