The correct option is C Nitrogen (7)
The electronic configuration and the number of valence electrons of the elements are given in the table below.ElementElectronic configurationNo. of valence electronsFluorine2,77Sodium2,8,11Nitrogen2,55Argon2,8,88The elements having the same number of valence electrons have similar chemical properties. Since both nitrogen and the given element have five valence electrons, their chemical properties would be similar.