Answer:
D. Ramesh and Ravi are correct, but they are using different measurement scales.
\Huge{\underline{\textrm{Explanation}}}Explanation
Here, Ravi says that his body temperature is 100 degrees, but does not mention that whether it is 100 degrees Celsius or 100 degrees Fahrenheit. When the temperature of a human body is more than 100.4 degree Fahrenheit (38°C), or near to it, the person is considered to have fever.
The boiling point of water is 100 degrees Celsius and not 100 degrees Fahrenheit.
Thus, they both are using different measurement scales.