The longest river in the world is the Nile. Therefore, the correct answer is (D) Neil (Nile). The Nile River is a major north-flowing river in northeastern Africa and is generally considered the longest river globally, with a length of approximately 6,650 kilometers (4,130 miles).

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.

Downs grasslands, commonly known as "downs," are extensive grassy plains found in Australia. These grasslands are a distinctive feature of the Australian landscape, characterized by vast expanses of open grassy areas. They play a crucial role in supporting unique ecosystems and biodiversity in Australia. Downs are often associated with pastoral activities and are utilized for grazing livestock, especially in regions with a semi-arid to arid climate. These grasslands contribute to the ecological diversity of the Australian continent.

Arakan Yoma is the extension of the Himalayas located in (D) Myanmar. The Arakan Yoma mountain range runs through the western part of Myanmar (Burma) and extends into southeastern Bangladesh.

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.

The headquarters of the World Bank is in Washington D.C. United States of America (USA).