What is the difference between a mark-and-sweep collector and a copying collector?

A Mark-and-sweep never reclaims memory, while copying collectors always do B Copying collectors require manual memory management while mark-and-sweep is fully automatic C Mark-and-sweep traverses from roots to mark live objects and then frees unmarked memory in place; a copying collector instead copies live objects into a new region, naturally compacting memory and leaving fragmentation behind D Mark-and-sweep can only be used with reference counting, while copying collectors cannot