What is the difference between internal and external fragmentation in memory management? Select the most accurate explanation.

a) Internal fragmentation occurs when the size of a memory block is smaller than the size of the data it should hold, while external fragmentation occurs when the size of a memory block is larger than the size of the data it should hold.

b) External fragmentation causes memory allocation requests to fail even if the sum of the sizes of all free blocks is sufficiently large (due to fragmentation into several, smaller blocks). Internal fragmentation causes memory allocation requests to fail due to a lack of available free blocks, even if there was enough unused space within allocated blocks, due to over-allocation of memory.

c) Internal fragmentation is memory fragmentation caused by memory allocations performed by your application (thus internal). External fragmentation is memory fragmentation caused by memory allocations performed by other applications in a separate address space (thus external).

d) Internal fragmentation occurs when there is not enough contiguous free memory to hold new data, while external fragmentation occurs when free memory is not used because it is too small to hold new data.