The correct order of melting point is

We need to determine the correct order of melting points for the alkaline earth metals Be, Mg, Ca, and Sr.

The melting points of these metals do not follow a simple trend because of differences in crystal structure. Beryllium adopts a hexagonal close-packed structure and melts at 1287°C, magnesium also has a hexagonal close-packed structure with a melting point of 650°C, calcium crystallizes in a face-centred cubic lattice and melts at 842°C, and strontium forms a face-centred cubic arrangement and melts at 777°C.

Since beryllium has the highest melting point (1287°C), followed by calcium (842°C), then strontium (777°C), and finally magnesium (650°C), arranging them in decreasing order gives $$\text{Be}(1287°C) > \text{Ca}(842°C) > \text{Sr}(777°C) > \text{Mg}(650°C)$$.

This sequence corresponds to Option C, so the correct answer is $$Be > Ca > Sr > Mg$$.