Question

which are limiting nutrients for plant growth?
water and nitrogen
nitrogen and carbon
carbon and phosphorus
phosphorus and nitrogen

Explanation:

To determine limiting nutrients for plant growth, we analyze each option:

• Water is not a nutrient (it's a resource), so "water and nitrogen" is incorrect.
• Carbon is abundant in the atmosphere (plants get it via photosynthesis from CO₂), so options with carbon (nitrogen and carbon, carbon and phosphorus) are incorrect.
• Phosphorus and nitrogen are often in short supply in soils, limiting plant growth (they're essential macronutrients).

Answer:

D. phosphorus and nitrogen