True because evryone reacts a different way
Ionic compounds are compounds composed of a metal as the cation (positive charge) and non-metals as anion (negative charge). Covalent compounds are composed of both non-metals. In this respect, a) water is covalent b) covalent c) ionic d) ionic e) covalent f) ionic.
Earth's magnetic field doesn't have much to do with tectonic plates. But both are caused by movement of the magma. The magnetic field is caused by electrical currents flowing in the magma, roughly parallel with the Equator. Tectonic plates move around the surface of the Earth over the liquid magma.
So I'd go with B. mantle convection currents
