Question

Compounds are formed when the atoms of two or more elements are chemically combined.

Answer 1

Fully donating an electron results in an ionic bond, so A is the correct answer.

In comparison, B, a hydrogen bond, is a bond that forms between an H in one compound and an O, N, or F in another.  It is among the strongest of intermolecular forces, while ionic/covalent bonds are intramolecular.

C, a covalent bond, is a bond that forms when atoms share electrons instead of donating them.