The correct answer is A) Absolute reading of a measured temperature in degrees Celsius. The Kelvin temperature scale is an absolute temperature scale that sets the zero point at absolute zero, the lowest possible temperature. This corresponds to the absolute reading of a measured temperature in degrees Celsius, where 0 Kelvin is equivalent to -273.15 degrees Celsius. The other options are incorrect because the Kelvin scale does not directly correspond to degrees Fahrenheit (option B) or degrees Rankine (option C), which is a temperature scale based on Fahrenheit.