Concept:Temperature in Kelvin is converted to Celsius by subtracting 273 from the Kelvin value.Explanation:The relationship between Kelvin and Celsius is:T(∘C)=T(K)−273Substitute the given value 20K into the equation:T(∘C)=20−273=−253∘CThus, 20K is equivalent to −253∘C.Answer:A. −253∘C