The correct answer is b) Red.
Iron oxide is a common mineral that is found in soil. It is responsible for the red, yellow, and brown colors of many soils. The amount of iron oxide in a soil can vary depending on the type of soil and the climate. Soils that are high in iron oxide are often called “red clay” or “red earth”.
Option a) Black is incorrect because black soil is typically rich in organic matter. Option c) Grey is incorrect because grey soil is typically low in iron oxide and high in clay. Option d) White is incorrect because white soil is typically high in calcium carbonate.