Read the following passage about future challenges and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.

The world faces numerous challenges in the coming decades. Among these, climate change remains one of the most pressing issues. Rising temperatures, melting ice caps, and severe weather patterns are disrupting ecosystems and threatening livelihoods. The challenge is not just to reduce greenhouse gas emissions but also to adapt to the changing environment. Governments and organizations worldwide are working toward renewable energy solutions and sustainable practices.

Another significant challenge is technological advancement. While innovations like artificial intelligence and robotics promise efficiency and convenience, they also raise concerns about job displacement and ethical implications. Workers in industries such as manufacturing and transportation fear being replaced by machines, leading to debates about how society should balance progress with employment security.

Demographic changes present additional difficulties. Many developed countries are experiencing aging populations, which strain healthcare systems and pension funds. In contrast, some developing nations struggle with overpopulation, leading to inadequate resources and infrastructure. Addressing these challenges requires global cooperation and creative problem-solving, such as improving education and investing in healthcare.

Finally, social inequality and political instability are growing threats to global peace and development. Disparities in wealth, access to education, and political power often result in unrest and conflict. Governments, non-profits, and individuals must work together to create fairer systems and promote inclusivity to ensure a stable and prosperous future.

In which paragraph does the writer mention demographic challenges?