Which of the following is not an explicit UN Sustainable Development Goal (SDG)?

The reason why access to affordable, clean nuclear energy is not an explicit UN Sustainable Development Goal (SDG) is that it does not appear in the official list established by the UN. The UN SDGs consist of 17 goals that address various global challenges, and while they include ambitions related to energy, such as ensuring access to affordable, reliable, sustainable, and modern energy for all (Goal 7), they do not specifically mention nuclear energy as a pathway.

By contrast, the other options refer directly to specific SDGs. Ending poverty in all its forms everywhere is Goal 1, ensuring healthy lives and promoting well-being for all ages corresponds to Goal 3, and taking urgent action to combat climate change is articulated in Goal 13. Each of these goals encompasses broad and well-defined targets aimed at achieving significant global improvements across economic, social, and environmental domains.