Answer:
B
Step-by-step explanation:
A: The speed in which the liquid moves is irrelevant, as long as it moves.
B: This will show the temperature: expansion -> bigger number -> hotter, and vise versa. You may already know that mercury expands and contracts with the change in temperature, without changing state. That is why the first thermometers used mercury.
C: No change of state is needed in a thermometer, and may actually cause it to break.
D: Adhering to a surface will cause the liquid to be unable to move, which shouldn't happen.