The major components in "Gun Metal" are:

We need to identify the major components of "Gun Metal."

Gun metal is a well-known alloy that was historically used for making guns. It is a type of bronze alloy. The major components of gun metal are copper (Cu), tin (Sn), and zinc (Zn), typically in the approximate ratio of 88% Cu, 10% Sn, and 2% Zn.

Now let us check the other options. Duralumin contains Al, Cu, Mg, and Mn. German silver contains Cu, Zn, and Ni. Stainless steel contains Fe, Cr, and Ni.

Hence, the correct answer is Option A.