On converting 25°C, 38°C and 66°C to Kelvin scale, the correct sequence of temperature will be

Kelvin is the SI unit of temperature.
To change a temperature on the Kelvin scale to the Celsius scale, subtract 273 from the given temperature.
To convert a temperature on the Celsius scale to the Kelvin scale you have to add 273 to the given temperature.

Hence, 25°C+273= 298 K, 38°C+273= 311 K and 66°C +273= 339 K.