Which one of the following major soil types of India is typically formed under classic monsoonal climatic conditions with alternating wet and dry seasons?

Introduction / Context:
Soils in India are closely related to climate, parent rock and vegetation. The monsoonal climate, with its strong seasonal contrast between heavy rainfall and dry periods, leads to particular soil forming processes. This question focuses on identifying which soil type is classically associated with typical monsoonal conditions, especially intense leaching during rainy seasons followed by drying out later.

Given Data / Assumptions:
• Soil types listed are black soils, red soils, laterite soils and none of the above. • Typical monsoonal conditions mean heavy seasonal rainfall followed by a marked dry season. • We assume classic textbook definitions of major Indian soil groups. • The question asks which soil is formed under these monsoonal conditions.

Concept / Approach:
Laterite soils are widely recognised as the result of intense leaching in hot, wet tropical and monsoonal climates. Under heavy rainfall, soluble bases like calcium and sodium are washed away from the upper layers, while iron and aluminium oxides remain and give the soil a characteristic reddish or yellowish colour. During the dry season, these residues harden, forming a lateritic crust. Black soils are more associated with basaltic parent rock and moderate rainfall, while red soils develop where there is less intense leaching. Therefore, laterite soils best match the description of soil formed under typical monsoonal conditions.

Step-by-Step Solution:
Step 1: Recall that laterite comes from a word meaning brick like, referring to the hardened crust formed in tropical monsoon regions. Step 2: Recognise that laterite formation involves strong chemical weathering and leaching due to high rainfall and temperature. Step 3: Note that monsoonal climates of coastal Western Ghats and parts of north east India are classic laterite soil regions. Step 4: Black soils are mainly linked with basaltic lava regions of Deccan and moderate rainfall, not the most intense monsoon leaching zones. Step 5: Red soils appear under less intense leaching where iron is present but bases are not completely washed away. They are not the classic example of typical monsoonal leached soils. Step 6: Therefore, laterite soils of high rainfall monsoon regions are the correct choice.

Verification / Alternative check:
Indian geography textbooks consistently describe laterite soils as the product of leaching under high temperature and heavy rainfall, typical of tropical monsoon conditions. They mention that large tracts of Kerala, Karnataka, Tamil Nadu uplands and parts of north east India have laterite soils because of such climate. In contrast, black soils are called regur and are associated with cotton, not with extreme monsoonal leaching, while red soils occupy large parts of the plateau under moderate rainfall.

Why Other Options Are Wrong:
Black soils form over basaltic parent rock under moderate rainfall and have high clay content and moisture retention capacity, which is not specifically a result of intense monsoonal leaching. Red soils are linked with weathered crystalline rocks where iron oxides give red colour, but they are not as strongly associated with the classic monsoon laterisation process as laterite soils. None of the above is incorrect because laterite soils clearly fit the description of soil formed under typical monsoonal climatic conditions.

Common Pitfalls:
Students sometimes confuse red soils with laterite soils because both can have reddish colour. However, laterites are more strongly leached and often harder, forming crusts. Another mistake is to select black soil due to its famous link with cotton, forgetting that the question is about climate driven formation under monsoon conditions. Always associate typical monsoonal leaching with laterite soils.

Final Answer:
The soil type formed under typical monsoonal conditions is laterite soils of high rainfall monsoon regions.