D, since it can hold up to 10 electrons
Some similarities between deserts and rainforests are that they support complex ecosystems, are powered by the sun/photosynthetic plants, are dangerous/mostly uninhabitable for humans, due to both conditions and wildlife, and are found mostly in the tropics
The largest atomic radius has Ba,because they are all metals of 2nd group,but as you know when you go down upright in the periodic table the metallic features getting stronger but also orbital layers increasing,and you can say more layers larger atomic radius.Hope I helped,sorry for English