simple harmonic motion

Question

Simple harmonic motion (SHM) is a technical term used to describe a certain kind of idealised oscillation. Practically all the oscillations that one can see directly in the natural world are much more complicated than SHM. Why then do physicists make such a big deal out of studying SHM?

A: It is the only kind of   oscillation that can be described mathematically

B: Any real oscillation can be analysed as a superposition (sum or integral) of SHMs      

    with different   frequencies.

C: Physics is concerned mainly with the unnatural world.

D: Students are too stupid to appreciate the real world.

E: It is good torture or students