Agricultural Development

Nitrogen fertilizers provide reactive nitrogen to soils. When soil microorganisms transform this nitrogen through nitrification and denitrification, some may be released as nitrous oxide, a powerful greenhouse gas. Excess application, poor timing, and waterlogged or poorly managed soils can increase losses. Improved fertilizer efficiency and soil management can reduce emissions, so D is correct.

The governing concept is education as a component of human development and human capability formation. Education develops literacy, knowledge, practical skills, critical thinking and the ability to make informed decisions. It can improve employment prospects, social participation, health awareness and problem-solving, so option B is correct. Education may indirectly influence land-use decisions or knowledge about weather, but those are only possible applications, not its sole importance. It is also not intended simply to increase population. Human geography studies education because differences in educational access help explain variations in opportunity, productivity, mobility and quality of life between places.

Soil is a basic agricultural resource because it anchors plant roots and stores water and dissolved mineral nutrients. Plants obtain essential elements from the soil solution, while the soil structure gives roots physical support and permits air and water movement. The quality of soil therefore influences germination, plant growth and crop yield. Option B is correct because it includes both major functions: supplying nutrients and providing support. Option A confuses soil colour with its agricultural role; option C is incorrect because soil does not stop rainfall; and option D is unrelated to soil formation or farming.