Answer:
B. Melbourne is at a lower latitude than St. Louis.
Step-by-step explanation:
Given that the higher the latitude of a place, (which means that the place is distant from the equator) the colder the region and the lower the latitude (which implies that the place is nearer to the equator) the sunny the region.
Hence, the temperature was much colder (in St. Louis) than it was in Melbourne, because "Melbourne is at a lower latitude than St. Louis."