(a) Elements A and D are cations because they have less than 4 electrons in their valence shell which they will donate to become electropostive .
(b) Elements C and E are anions because they have 7 electrons in their valence shell and can accept one electron to become electronegative
(c) B is an inert gas as it has 8 electrons in its valence shell and can neither loose electrons or gain electrons to become a cation or anion