<span>The word that mostly has a positive connotation is A, request, because you are not directly telling the person to do this or that but instead you ask them if they could do this/that.</span>
To request means to ask, usually, though not necessarily, in a polite way for something, commonly a favor with which one needs assistance or help.
Again, though it is not necessarily always the case, the action of requesting is often accompanied by humility and gratitude on the side of the person asking for something, and it is accompanied by satisfaction on the side of the one who is being asked.
