Explanation:

African Savannah: Option 1 is in correct as it do not fit the extreme climate and scanty rainfall criteria.

The climate is usually warm and temperatures range from 68° to 86°F (20 to 30°C). Savannas exist in areas where there is a 6 - 8 month wet summer season, and a 4 - 6 month dry winter season.

Option 2 is correct as Steppe's climate is continantal with extremes of temperature. Nomadic tribes like Kirghiz are found. Rainfall is expected to be light. African Savannah gets moderate rainfall.

Option 3 is incorrect-Though North American Prairie also have extreme climate and scanty rainfall but it do not possess nomadic herders, The farmers here use mechanized equipment and do wheat cultivation on large scale.

Option 4 is incorrect-Siberian Tundra- The temperature may reach -40 degrees Fahrenheit. Summers are cool with temperatures of 37 degrees to 54 degrees Fahrenheit. Precipitation is only 6 to 10 inches per year including melted snow. But it also do not possess nomadic herders. The population there is primarily involved in hunting and gathering.