The answer is C I hope I’m not too late
Pay attention in class, ask for help when you need it, stay out of trouble. That's what I do and I have A's is all classes except math which is a B. (sorry not trying to brag)
Quantum mechanics<span> (QM -- also known as </span>quantum physics<span>, or </span>quantum<span> theory) is a branch of </span>physics<span> which deals with physical phenomena at nanoscopic scales where the action is on the order of the Planck constant. It departs from classical </span>mechanics<span> primarily at the </span>quantum<span>realm of atomic and subatomic length scales.</span>