Question 16: Purpose of DLLs in Windows By using DLLs, Windows:

DLLs (Dynamic Link Libraries) are designed to allow multiple programs to share the same library code without duplication, reducing memory overhead and promoting code reuse. While DLLs can indirectly improve performance by reducing memory usage, their primary purpose is code sharing. Multitasking and hardware communication are OS-level features not directly enabled by DLLs.

Step-by-step Derivation:
DLLs are libraries containing reusable code that can be linked dynamically at runtime by multiple applications. The core benefit is: (1) Multiple programs can load and use the same DLL in memory, avoiding redundant copies of the same code; (2) This reduces overall system memory consumption; (3) Updates to shared libraries can benefit all dependent applications. Option A (saves processing time) is secondary—the time saving comes from reduced memory I/O, not primary CPU acceleration. Option B (multitasks) is handled by the OS scheduler, not DLLs. Option D (hardware communication) is handled by device drivers and APIs, not DLLs directly.