Acids are ionic compounds that break apart in water to form a hydrogen ion. The strength of an acid is based on the concentration of hydrogen ions in a solution. The more hydrogen ions, the stronger the acid. Bases are ionic compounds that break apart in water to form negatively charged hydroxide ions. The strength of the base is based on the concentration of hydroxide ions.
Hence, letter C is the correct answer.
The equation is already balanced
2AgNO3 + MgCl2 => 2AgCl + Mg(NO3)2
Ionic bonds are formed when one of the two atoms that are reacting has excess electrons and transfer the electrons to the atom that is deficient in electrons. During the formation of the ionic bond, one of the reacting atoms will donate electrons and form positive ion.