healthy oceans and forests\na.\nare a carbon dioxide source\n\nb.\nare a carbon dioxide sink\n\nc.\nare an…

healthy oceans and forests\na.\nare a carbon dioxide source\n\nb.\nare a carbon dioxide sink\n\nc.\nare an example of positive feedback\n\nd.\ncontribute most of the greenhouse gases

healthy oceans and forests\na.\nare a carbon dioxide source\n\nb.\nare a carbon dioxide sink\n\nc.\nare an example of positive feedback\n\nd.\ncontribute most of the greenhouse gases

Answer

Brief Explanations:

  • Option A: Carbon dioxide sources release CO₂ (e.g., fossil fuel burning). Oceans/forests absorb, not release, so A is wrong.
  • Option B: A carbon sink absorbs CO₂. Oceans dissolve CO₂, forests use it in photosynthesis, so healthy oceans/forests are sinks. This is correct.
  • Option C: Positive feedback amplifies changes. Oceans/forests stabilizing CO₂ is negative feedback (or just sinks), so C is wrong.
  • Option D: Greenhouse gases (e.g., CO₂, CH₄) are mostly from human activities (fossil fuels, agriculture), not oceans/forests, so D is wrong.

Answer:

B. are a carbon dioxide sink