The activity series goes top to bottom, most active to least active elements, going: Li, K, Ba, Sr, Ca, Na, Mg, Mn, Zn, Fe, Cd, Co, Ni, Sn, Pb, H, Cu, Ag, Hg, Au.
Thus, your list of metals would go from most reactive to least reactive: Li, K, Mg, Zn, Fe, Cu, Au
I had to look for the options and here is my answer: The two requirements for nuclear fusion that are needed to be met in order for the elements hydrogen and helium fuse to make heavier elements are extremely high temperatures and density. Hope this helps.
