Which option would generate the least amount of particulate matter?

The option that generates the least amount of particulate matter is a nuclear power plant. Nuclear power plants operate through a process of nuclear fission that generates heat, which is then used to produce electricity. This method does not involve combustion of fossil fuels, biomass, or organic material; therefore, it does not directly release particulate matter into the atmosphere as a byproduct of its energy production processes.

In contrast, a city bus running on diesel emits particulate matter due to the incomplete combustion of diesel fuel, which releases soot and other particulates. A wood burning stove produces particulate matter from the combustion of wood, which releases ash and soot into the air. Additionally, natural prairie wildfires generate substantial amounts of particulate matter as they involve the combustion of organic matter in the form of plants and vegetation, resulting in significant smoke and soot emissions.

Given these mechanisms, the nuclear power plant stands out as the cleanest option in terms of particulate matter emissions, making it the most environmentally friendly choice among the provided alternatives.