Among the elements listed (Au - gold, Zn - zinc, S - sulfur, Si - silicon), zinc (Zn) has the most metallic character.
Metallic character increases as you move down a group in the periodic table and decreases as you move from left to right across a period. Zn is located in group 12 and is a metal, while Au (gold) is also a metal but is further to the right in the periodic table. Sulfur (S) and silicon (Si) are nonmetals and metalloids, respectively, which means they have even less metallic character compared to metals like Zn and Au. Therefore, Zn is the most metallic in this list.