Which of the following are the primary causes of climate change? a) Excessive burning of fossil fuels b) Exploding numbers of automobiles driven by oil c) Increasing solar flares d) Heavy deforestation Select the correct answer using the code given below:

The correct answer is B.

Statements a, b and d are human-driven causes. Burning fossil fuels for power, industry and transport releases carbon dioxide, which now stands above 400 ppm against about 280 ppm before industrialisation. Statement b is a specific form of the same process, since oil-fuelled vehicles are a major source of transport emissions, so it overlaps with a rather than being a separate cause. Heavy deforestation adds carbon when trees are burnt or decay, and it also removes a sink that would otherwise absorb CO2.

Statement c is wrong. Solar flares are short bursts of activity, and solar output varies over the roughly 11-year cycle by only a small fraction. The IPCC attributes the warming since the mid-twentieth century mainly to human activity. Solar variation is a natural factor with a minor role, not a primary cause.

The core concept is the enhanced greenhouse effect, driven by anthropogenic emissions and the loss of carbon sinks. For Mains, link this to India's NDC commitments under the Paris Agreement and to the trade-offs between energy access, transition and forest policy.

Trap: Aspirants either treat statement b as an independent cause or assume solar activity is comparable to fossil fuel emissions. Statement b repeats a, and solar variation is minor.