The correct answer is: Conventional memory.
Conventional memory is the first 640 kilobytes (KB) of a computer’s memory. It is used by the operating system (OS) and applications. When an application is started, it is loaded into conventional memory. If there is not enough space in conventional memory, the application will not start.
Expanded memory is a type of memory that is used to supplement conventional memory. It is typically used by applications that require more memory than is available in conventional memory. Expanded memory is managed by a device driver called EMM386.EXE.
Cache memory is a type of memory that is used to store data that is frequently accessed by the CPU. It is located on the motherboard and is much faster than main memory.
Virtual memory is a technique that allows the OS to use disk space to simulate additional RAM. This is useful when there is not enough physical RAM to run all of the applications that are currently open.
In conclusion, the memory which allocates space for DOS and application is called conventional memory.