A template of a Venn diagram representing common and differentiating characteristics of covalent and ionic bonds is shown.
Which of the following characteristics can be written only in space A?

Formed between atoms of similar electronegativities
Formed between two metal atoms mostly found on the left of the periodic table
Formed between two non-metal atoms mostly found on the right of the periodic table
Formed between an atom that tends to lose electrons and an atom that tends to gain electrons