Final answer:
The two elements that are most similar are Cu (Copper) and Ag (Silver) because they belong to the same group in the Periodic Table, hence, they possess similar properties.
Step-by-step explanation:
The elements that are most similar are option C, Cu(Ag). Under the periodic table, elements that are in the same group (or column) have the most similarities. This is because elements in the same group have the same number of electrons in their outermost shell, leading to similar chemical properties. Both Copper(Cu) and Silver(Ag) belong to group 11 of the Periodic Table, making their properties very similar. This includes characteristics like their shiny appearance, high electrical and thermal conductivity, and resistance to oxidation.
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