Francis is learning about dissolving at school. She reads descriptions about the rate of dissolving from four of her friends.

George: The rate of dissolving can be fast or slow. The only thing you can do to speed up the rate of dissolving is to make the temperature hotter.
Manuel: The rate of dissolving can change. The rate of dissolving gets faster when the particles are smaller, the temperature is hotter, or the mixture is stirred.
Kim: The rate of dissolving speeds up when the particles are larger and the temperature is hotter. Stirring the mixture also helps increase the rate of dissolving.
Chris: The rate of dissolving can speed up or slow down. Heating a mixture, stirring a mixture, or using smaller particles will slow down the rate of dissolving.

Which of her friends has the best description about the rate of dissolving?

A George
B Manuel
C Kim
D Chris