Answer:
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D. Burning of fossil fuels</u></h2>
Explanation:
Option A; Volcanic eruptions happen all over the world. These release large quantities of gases. Although these release gases, these are not do to human activity. Volcanic eruptions are natural disasters. Since theses are natural, we can eliminate option A.
Option B; Wildfires also give off large amounts of gases. Wildfires burn through trees and will destroy nearly everything in its reach. Many wildfires have been started by humans, but they also can start naturally from something like lightning. These wildfires are being put out but not too quickly. So option B will can not eliminate it yet.
Option C; Planting trees can be done naturally. This process is being sped up by humans. Even though humans are a huge part of this, trees only slow down the rate in which carbon dioxide enters the atmosphere. So we can eliminate option C.
Option D; Burning fossil fuels is the main source of electricity for humans. About 60% of electricity is from fossil fuels. Upon burning fossil fuels, like coal, it releases huge amounts of gases. Mainly carbon dioxide. So we will not eliminate option D.
So we are left we B and D. Since option D involves more human activity than option B, D is the option that makes the most sense
Hope this helps and have a great day! :D
