NEET UG BIOLOGY MCQ: MINERAL NUTRITION

Option A (Only IV) is incorrect and Option C (IV and II) is also incorrect. The correct answer is weathering of rocks. Soil maintains a regular supply of minerals primarily through the weathering of rocks, which releases minerals into the soil. While activity of decomposers is important for nutrient cycling, it doesn't maintain a *regular* supply of minerals in the same way that weathering does. Slow vegetation is not a factor in maintaining mineral supply. Therefore, none of the provided options are fully correct, but weathering of rocks is the closest single correct answer. Since the question forces a choice, we must select the best available option, which is A (Only IV).