In the reaction between zinc and iodine, zinc iodide is formed. Which is being oxidized? 

An atom that has contributed electrons is an oxidised atom, and an atom that has taken electrons is a reduced atom. Typically, the acceptor p block elements receive electrons from the s block elements as donors.

Let's first comprehend the idea of oxidation and reduction before looking at the reaction.
In terms of electrons, the processes of oxidation and reduction are the removal of electrons from an element, respectively. The species that donated electrons is referred to as being oxidised, whereas the species that received electrons is referred to as being reduced.
Zinc iodide is created through the interaction between zinc and iodine. The response can be expressed as:

$Zn+I_2\to Zn{I}_2$

Here, the zinc is a metal, and we are aware that metals prefer to give. Because their valence electrons are not firmly linked, metals can quickly shed them.
Halogen iodine requires one more electron to complete its octet. As a result, it will be strongly electronegative and readily accept an electron.
The Zn metal has therefore contributed two electrons to this process, which are then captured by iodine atoms, one electron by each I atom.
As a result, the iodine is reduced while the zinc metal is oxidised.
 So, the option (C) is the correct answer.