What is the benefit of deep soil in plains?

Correct answer: Roots get help to spread and take nutrients

The direct answer is A: deep soil helps roots spread and obtain nutrients. Soil is the layer in which plants anchor their roots and find water and minerals. Plains often have deep, deposited alluvial soil, so roots can grow downward and sideways instead of meeting hard rock quickly. Step by step: deep soil gives roots more space; larger roots can absorb more water and minerals; therefore plants can grow more successfully. Option A is correct because it describes this benefit. Option B is wrong because soil depth does not stop sunlight; sunlight comes from above and reaches plants. Option C is wrong because deep soil does not always blow away, and vegetation may hold it with roots. Option D is wrong because soil depth cannot stop rainfall. Memory cue: deep soil means deep root space and better nutrient access.