Answer:
A
Explanation:
Halogens have 7 electrons in their valence shell and requires just one electron to achieve their stable structure. Because of this they have high electron affinity and hence high electronegativity and they are strong oxidizing agents. Oxidation is the loss of electrons . Halogens have a high readiness to take electrons which a metal loses thereby oxidizing it. The other options are wrong as they involve compounds and not the elemental form as stated in the question.
