About 15 percent of global greenhouse gas emissions come from agricultural practices. This includes nitrous oxide from fertilizers; methane from livestock, rice production, and manure storage; and carbon dioxide (CO2) from burning biomass, but this excludes CO2 emissions from soil management practices, savannah burning and deforestation. Forestry and use, and land-use change account for another 17 percent of greenhouse gas emissions each year, three quarters of which come from tropical deforestation. The remainder is largely from draining and burning tropical peatland. About the same amount of carbon is stored in the world's peatlands as is stored in the Amazon rainforest.

Correct Option (B)

The passage explicitly details that agricultural practices contribute approximately 15 percent of global greenhouse gas (GHG) emissions, and forestry, land-use, and land-use change account for another 17 percent. It further specifies that tropical deforestation and the draining/burning of tropical peatlands are significant sources within these categories. Given that these land-based activities are identified as major contributors to GHG emissions, the most logical inference is the imperative to modify land-use practices to mitigate climate change.

Incorrect Options:

Option (A): While the passage highlights emissions from agricultural practices, it does not advocate for a specific solution such as an immediate global replacement of conventional farming with organic farming. This inference extends beyond the scope of the provided text.

Option (C): The passage focuses on identifying sources of greenhouse gas emissions related to agriculture and land use. It does not discuss the existence or absence of technological solutions to the problem of greenhouse gas emissions, making this statement an unsupported claim.

Option (D): The passage mentions that significant carbon is stored in tropical peatlands and the Amazon rainforest. However, the primary emphasis is on the emissions generated from land-use changes in these areas (e.g., tropical deforestation, draining/burning peatlands). The passage does not assert that tropical areas are the chief sites of carbon sequestration globally, nor is that the central inference intended from the discussion of emissions.