Answer:
C
Explanation:
You can use process of elimination to get your answer.
A & D would be advantages of using celcius thermometers so they are eliminated.
B can be useful if you need to know what temperature water boils at, making it an advantage so it is eliminated.
This leaves C, the only option choice that sounds like a disadvantage. This is seen as it explains how the mercury inside could harm the user if the thermometer.
