The answer is B. Continental Drift (Confidently)
Water is an amphoteric compound. This means it could be a base or an acid, depending on the substance it is to be reacted with. In this case, water is a base because HF is an acid. Now, if the reactant is an acid, its form after the reaction is called the conjugate pair. Since HF became F⁻, <em>the acid-conjugate base pair is: HF and F⁻.</em>
I would say copper, silver, and tin, since an alloy is a mixture of metals and metalloids.
