I think that the answer is A because if you think about water for an example. When water turns into ice, it's still technically water, just the molecules are frozen. The water is physically changed. It could also see why you think it is B but I don't think so completely. It doesn't really make sense to me. So I'd choose A. It's definitely not C or D.
acid
when a metal hydroxide reacts with acid it forms a salt and water, for example:
lithium hydroxide + hydrochloric acid → lithium chloride (the salt) + water
