Which of the following is the strongest oxidizing agent?
Correct: B
An oxidizing agent is a substance that gains electrons and is reduced. The stronger the oxidizing agent, the more readily it is reduced. Fluorine (F₂) has a very high electronegativity and a strong tendency to gain electrons. Li⁺ and K⁺ are already in their highest oxidation state, so cannot act as oxidizing agents. I₂ is a weaker oxidizing agent than F₂.