Final answer:
The proportion of human-caused greenhouse gas emissions resulting from activities in the global food system is 10%.
Step-by-step explanation:
The proportion of human-caused greenhouse gas (GHG) emissions resulting from activities associated with the global food system is 10% (Option a).
According to available estimates, agriculture alone is responsible for 10 to 12 percent of global emissions. The production, transport, processing, storage, waste disposal, and other life stages of food production contribute to greenhouse gas emissions. Livestock for meat production produces more greenhouse gas emissions than all forms of fossil fuel-based transportation combined.
Therefore, option a) 10% is the correct answer.