The most appropriate response is: "An ionic bond is likely because they will want to give away two valence electrons in order to become stable."
Group 2 elements, also known as alkaline earth metals, have two valence electrons. They typically lose these two electrons to achieve a stable electron configuration, often forming cations. When they bond with nonmetals, which tend to gain electrons, an ionic bond is formed as the metal gives away its valence electrons to the nonmetal.