In lines 15-18 of "out,out" the speaker suggests that he or she

We do not witness what exactly happened but we do read that the saw "leaped" or seemed to leap as if it was a force unto itself. It follows that the boy has "given the hand" to the saw. It is the saw that is in control, not the boy. The saw becomes a personification of a human and the boy, in subservience, gives his hand to it. I would pick C.