A context switch (also sometimes referred to as a process switch or a task switch) is the switching of the CPU (central processing unit) from one process or thread to another.

hence the answer is none

answer is all. any of the instruction comes cpu has to make context switch to other process

The answer is c) System Calls

Context switch is switching the process from one location that as been specified.
Similiarly the system call call some other procedure during the execution of another process.

On wikipedia
http://en.wikipedia.org/wiki/Context_switch

The 3 reasons re given.
Floating point unit, uses its own set of registers for doing the floating point arithmetic,
These are registers used specifically for floating point arithmetic and are completely separate from the native x86 registers used for integer arithmetic. These constitute the floating point context of the CPU. This (apart from the native processor context) need to be saved/restored with each process context switch.


System Calls are Interrupt itself.

And Privilege instructions e.g. initiate I/O involve load/save from protected memory
Operating systems hide privileged instructions and provide virtual instructions to access and manipulate virtual resources, e.g., I/O to and from disc files

Hence answer should be "ALL" .

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