i added this table for some
here are some examples
metals: they are hard and shiny, strong, and easy to shape. they are used for many industrial purposes. this group includes iron, gold, silver, chromium, nickel, and copper, some of which are also noble metals.
non-metals: a chemical element (as boron, carbon, or nitrogen) that lacks the characteristics of a metal and that is able to form anions, acidic oxides, acids, and stable compounds with hydrogen.
metalloids: physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor. metalloids have mixed properties which are difficult to characterize.
the answer is d because it is the only one that happens under water.