Identify the incorrect statements about group 15 elements :
(A) Dinitrogen is a diatomic gas which acts like an inert gas at room temperature.
(B) The common oxidation states of these elements are and +5.
(C) Nitrogen has unique ability to form multiple bonds.
(D) The stability of +5 oxidation states increases down the group.
(E) Nitrogen shows a maximum covalency of 6.
Choose the correct answer from the options given below :