Choose the most reasonable Celsius temperature for a high fever. 25 degrees Celsius, 39 degrees Celsius, or 101 degrees Celsius.

The most reasonable Celsius temperature for a high fever is 39 degrees Celsius, as it corresponds to about 102°F.
To determine the most reasonable Celsius temperature for a high fever among the given options, let's examine normal and feverish body temperatures:
Among the options:
Thus, the most reasonable Celsius temperature for a high fever is 39 degrees Celsius.
Answer:
39°C is considered a high temperature for a high fever, since the normal body's temperature is about 36.5 - 37°C and rarely reach 41 - 42°C, 25°C will be too low and 101°C is also an impossible answer.