Final answer:
Oxygen (O) is most likely to have an oxidation number of +3.
Step-by-step explanation:
The element Oxygen (O) is most likely to have an oxidation number of +3.
When oxygen forms compounds, its oxidation number is typically -2. However, in certain compounds such as peroxides (e.g., H2O2) and superoxides (e.g., KO2), the oxidation number of oxygen can be +1 and -1, respectively.
Therefore, out of the given options, Oxygen (O) is the element most likely to have an oxidation number of +3.
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