Which memory region is used for dynamic storage during program execution?

• A. Stack
• B. Heap memory
• C. Buffer
• D. ESI

Answer: (B)

Dynamic memory allocation uses the heap. This region is set aside for allocations that are requested at run time and can persist beyond the lifetime of a single function call. A memory allocator manages the heap, with operations like malloc/free (or new/delete in C++), allowing data structures to grow or shrink as needed and to outlive the current scope. In contrast, the stack holds automatic, function-scoped variables and return addresses, with memory management tied to function calls in a last-in-first-out manner—fast but limited in size and not suitable for long-lived dynamic storage. A buffer is just a general term for a piece of memory and can reside in either region depending on how it’s allocated. ESI is a CPU register, not a memory region.