Answer: Kelvin (K)
Step-by-step explanation:
As we know that there are seven fundamental SI units which are used to fine derived units. These are as follows:
1). Mass - Kilogram
2). Length - meter
3). Time - Seconds
4). Electric Current - Ampere
5). Amount of substance - Moles
6). Temperature - Kelvin
7). Intensity of light - Candela
Thus Kelvin would be the S.I. unit to use in measuring the temperature of hot liquid.