Which of the following metals does NOT react with water?

Zinc does not react with water, which makes it the correct choice in this context. Unlike alkali metals such as potassium, lithium, and sodium, which readily react with water to produce hydrogen gas and a corresponding hydroxide solution, zinc behaves differently. When zinc is placed in water, it does not undergo a visible reaction unless the water is in the form of steam or at high temperatures. This is due to zinc's position in the reactivity series, where it is less reactive than the alkali metals, which are known for their vigorous reactions with water. In contrast, the other metals listed, potassium, lithium, and sodium, are all alkali metals that react explosively or vigorously when they come into contact with water, showcasing their high reactivity.