G. Talk to manager about sending employee home for the good of the public health.
That's a good option if you feel like you might make the worker feel bad. You could talk to the manager, like its in his own best interest to not turn customers off with the possibility of germs in the food. Compliment the worker to the manager for trying his best and working hard, but suggest he needs to leave, then ask for a new cup. You'd probably get it comp'd too!
SHit this is easy, you'll notice the bitch that sneezes in my coffee by the fucking 3rd degree burns on hers or his face and the burnt off eyebrows. Fuck yo poilite shit