One of the following statements is incorrect with reference to biodiversity. Identify it.

• A
  The richest reservoirs of animal and plant life (high species richness) with few or no threatened species are called "biodiversity hotspots".
• B
  Biodiversity increases from higher altitudes to lower altitudes.
• C
  Biodiversity decreases from the equator to polar regions.
• D
  Depletion in genetic diversity of crop plants is mainly due to the introduction of better varieties with high yield, disease resistance, etc.