(a) If you rub your hands together, does the entropy of the universe increase, decrease, or stay the same?

(b) Choose the best explanation from among the following:

I. Rubbing hands together draws heat from the surroundings, and therefore lowers the entropy.

II. No mechanical work is done by the rubbing, and hence the entropy does not change.

III. The heat produced by rubbing raises the temperature of your hands and the air, which increases the entropy.