Which of the following describes a tropical rainforest?

• A. Very dry climate and nutrient-poor soil.
• B. Extreme cold; low biodiversity.
• C. Consistent climate; nutrient-poor soil; high biodiversity.
• D. Seasonal drought with sandy soils.

Answer: (C)

Tropical rainforests are characterized by warm temperatures and high, year-round rainfall, creating a stable, hot, humid climate that supports a huge diversity of life. Because rainfall is so abundant, nutrients are often quickly taken up by plants and rapidly cycled, so the soil itself tends to be nutrient-poor, with most nutrients stored in the dense biomass rather than in the soil. This combination of a consistent, warm, wet climate with nutrient-poor soil and very high biodiversity best matches the description of a tropical rainforest.

The other descriptions don’t fit: a very dry climate and nutrient-poor soil points to deserts or tropical dry forests; extreme cold with low biodiversity points to tundra; seasonal drought with sandy soils aligns with savannas or dry forests, not rainforests.