- Reclaiming memory from unused programs: Garbage collection focuses on reclaiming memory from unused objects, not programs.
- Removing all programs from memory: This is incorrect because garbage collection does not remove entire programs from memory.
- Reclaiming usable work space: This is the correct definition of garbage collection, which involves cleaning up unused memory spaces (such as unused objects or variables) to make room for new data.
- Removing larger programs to accommodate smaller programs: Garbage collection does not work by removing programs of any size to fit others.
Therefore, the correct answer is 3. Reclaiming usable work space.