Which of the Following Statements Regarding Valence Electrons Is Incorrect

Multiple Choice

Which of the following statements regarding valence electrons is incorrect?

A) The valence electrons are the electrons in the last-filled principal energy level.
B) For main-group elements, the number of valence electrons is equal to the number of electrons in the highest-energy s and p sublevels.
C) Except for helium, the Roman numeral group number corresponds to the number of valence electrons for the main-group elements.
D) The period number of an element equals the energy level of the valence electrons.
E) Elements in the p-block in the fourth period and below include their d electrons as part of their valence electron count.