In a liquid-in-glass thermometer, the liquid column is $2.0\,\text{cm}$ in length at $0^\circ\text{C}$. When the thermometer is heated to $100^\circ\text{C}$, the column length increases by $10.0\,\text{cm}$. If the measurement is taken from P, what is the length of the liquid column at $30^\circ\text{C}$?
- A$2.3\,\text{cm}$
- B$3.0\,\text{cm}$
- C$5.0\,\text{cm}$
- D$7.0\,\text{cm}$