Answer: More reactive non-metal is Sulfur (S).
Step-by-step explanation:
Non-metals are defined as the elements which have the tendency to gain electrons.
A reactive non-metal is the one which gains electrons easily.
In a periodic table, the reactivity of non-metals increases as we move across a period and decreases as we move down the group.
Sulfur belongs to group 16 and period 3 of the periodic table while Arsenic belongs to group 15 and period 4 of the periodic table.
Hence, Sulfur is a more reactive non-metal.