Of the three metals X, Y, and Z, X reacts with cold water, Y with hot water, and Z with steam only. Identify X, Y, and Z, and also arrange them in order of increasing reactivity.
a) X = Zn, Y = Mg, Z = Fe
b) X = Mg, Y = Fe, Z = Zn
c) X = Zn, Y = Fe, Z = Mg
d) X = Fe, Y = Mg, Z = Zn