Final answer:
The minimum number of frames allocated to a process is decided by the Operating System, which manages memory allocation based on various factors.
Step-by-step explanation:
The minimum number of frames to be allocated to a process is determined by the Operating System (OS). The OS is responsible for managing memory allocation, including the division of physical memory into frames and the allocation of a minimum number of frames to each process. It makes these decisions based on criteria like process size, process priority, and memory management policy, which varies from one operating system to another.
The amount of available physical memory is a factor that influences overall memory allocation strategy, but does not dictate the specific minimum number of frames per process. Instruction set architecture does also affect how memory is managed, but the actual minimum frame allocation is still a function of the OS. Thus, the correct answer is (b) Operating System.