Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.

Renewable energy sources are becoming increasingly important in the fight against climate change. Solar and wind power, ___(1)___, are two of the fastest-growing energy sources. Many countries have invested in these technologies to reduce dependence on fossil fuels and lower greenhouse gas emissions. Some nations try to harness sunlight and wind ___(2)___. Advancements in technology have also made these energy sources more efficient and accessible.
One key advantage of renewable energy is that it does not produce carbon emissions during operation. ___(3)___. Additionally, renewable energy ensures a stable electricity supply, as improving technologies enhance efficiency. Battery storage systems and smart grids help address power fluctuations, making renewable energy more reliable.
However, the transition is not without challenges. One major issue is the cost of infrastructure, whose development demands significant funding from governments. ___(4)___. Despite these difficulties, experts agree that increasing investment in renewable energy will contribute significantly to a more sustainable future. Many governments have implemented policies to support the development of renewable energy, and these efforts are expected to continue in the coming years. ___(5)___. As technology advances and costs drop, it will become more accessible, benefiting both the environment and the economy.