Option 1 -> The passage explicitly states India is leading global efforts through the International Solar Alliance.
Option 2 -> Hydropower exports to neighboring countries are not mentioned in the passage.
Option 3 -> While renewables are fossil fuel alternatives, this is not specifically mentioned as India's leadership initiative.
Option 4 -> Advancements in wind turbine design are not attributed to India in the passage.
Hence, Option 1: the International Solar Alliance -> The passage clearly states "With initiatives like the International Solar Alliance, the country is leading global efforts to harness the power of the sun," making this the specific mechanism through which India demonstrates its leadership in renewable energy. -> correct