The Intergovernmental Panel on Climate Change has issued which of the following statements?

The Intergovernmental Panel on Climate Change has issued which of the following statements?
 
  A) Climate change models can mimic present-day conditions only if human emissions are taken into account.
  B) Human climate alterations have not yet produced significant impacts on biological systems.
  C) Ocean acidification is not a problem because the ocean does not absorb carbon dioxide gas.
  D) Recent regional climate changes have not yet affected physical systems on Earth.
  E) The temperature increases observed since the mid-20th century are very likely due to natural causes.