If an element has atoms, in their ground-state, with 6 valence electrons, the element could be: (check all possible answers)

You included no options however the elements with 6 Valence electrons are;

Valence electrons refer to the electrons an element has on its outermost shell. The number of these electrons determines the charge that an electron will carry as it seeks stability.

It also determines which group the element will be in in the Periodic table. Elements with 1 valence electron for instance will be in Group 1 and elements in Group 16 will have 6 valence electrons.