This liquid is sometimes colored alcohol but can also be a metallic liquid called mercury. Both mercury and alcohol grow bigger when heated and smaller when cooled. Inside the glass tube of a thermometer, the liquid has no place to go but up when the temperature is hot and down when the temperature is cold. Mercury is very reactive and works best. But mercury is also very a radioactive element. So, if you break the thermometer, you could get in trouble (radio active posoning) Alcohol work well, it is not radioactive and can't kill you.
Okay, hope I helped
:)))
B is the correct answer for it
