Which of the following statements are incorrect about the elements Cs, Ne, I and F?

(a) F exhibits only negative oxidation state because it is the most electronegative element.(b) Cs exhibits only positive oxidation state because it is the most electropositive element(c) Ne is an inert gas, so it exhibits neither negative nor positive oxidation state.(d) I exhibits both positive and negative oxidation states e.g. -1, 0, +1, +3, +5 and +7 oxidation states are exhibited by I due to the presence of vacant d-orbitals).