What is the result of a redox reaction?

In a redox reaction, both reduction and oxidation occur simultaneously because these processes are interdependent. Oxidation refers to the loss of electrons and an increase in oxidation state, while reduction involves the gain of electrons and a decrease in oxidation state. For every electron that is lost by one species (oxidized), another species must gain that electron (reduced). This coupling of oxidation and reduction is what characterizes a redox reaction, resulting in a balance of electron transfer.

When looking at the options, the other choices do not accurately represent the nature of redox reactions: stating that only oxidation or only reduction occurs overlooks the integral relationship between the two processes. Similarly, suggesting that no changes in oxidation states occur contradicts the fundamental principle of redox reactions where there must be a change in oxidation states for the reaction to be classified as redox. Thus, the correct answer reflects the essential characteristic that both oxidation and reduction happen at the same time.